At 4:00, when the first lizard is carted away, I see my chance.
My invisible characters dig 1 grave about thirty minutes' walk
AWAY from town from where Sneedy is (GRAVE -- HERDING -- TOWN).
It is fairly decent, say about 6' deep, and 3'x6' in the
other dimensions.  While four people dig, a couple are scouting around
for wanderers (monsters or otherwise).  This should take about 1
hour, and will thus tie in with your "about 6:00" estimate.
(They have shovels to dig with, since they knew in advance what
they would be used for, and the ground is soft because it's recently
rained, and they had a day or two to scout around for a reasonable
burial site.  So they dig from 4:30 to 5:30, return to the
lizard site at 6:00, do the sleep's, bind up & gag  the two minor
characters.  Their throats will be slit, but not until they are about
ten minutes' ride from the site, and even then, a sack is used to
catch any trickles of blood, both there and as they ride on
(blood coagulates quickly, after death).  SO: not to get ahead of
myself:  before this throat-slitting, Clary and Hotefur put the two bodies
on horseback, under sacks (in case a wanderer is met), and ride for
the gravesite. Along the way, they slit throats and continue on.
If there is some chance of these dudes turning into undead (I don't
see why, but your dungeon world might work like that), then some holy
water is dumped on them after death.
  When they get to the grave, they hack the bodies into little
pieces (30 minutes worth of mutilation can do a LOT of damage),
careful to do the hacking IN the grave itself,
search the bodies carefully for gold, magic, etc.,
and to provide the ultimate false trail, they leave an Orc daggar
sticking in one of the bodies (this is the captured throwing daggar).
and three common arrows in the second.
They dump them into the grave, and bury them.  They then smooth over the
gravesite, and replant a few of the uprooted plants, scatter a few
branhes around there, etc. 
Needless to say, they occasionally peer around, pause & listen, etc.
But they are really out in the boonies, not near any road, not near
the lizard site, not even on a straight line between any two of the
lizard herd site, town, hill, road.  So only a wandering monster
might actually get them.  If it does, and it looks like they're
going to die, they'll jump into the grave (to make it look like
THEY were the ones murdered and almost buried, rather than vice versa.

After this, they ride back to the lizard site, clean it up (wipe up
any signs of what happened, look for clues and remove them, etc.),
say for 30 minutes, and then head back for town themselves.
So they'll arrive about 2 hours after everyone else.

------------


Meanwhile, at the time that Hotefur and Clary ride off with these two
corpses, Levi throws invisibility on Sneedy (yes, after tying him
up, blindfolding him, gagging him VERY securely, plugging up his
ears, and tying him -- besides all else -- to a 2' x 6' plank.)
(He couldn't wiggle his fingers, cough, say anything, etc., even if
he woke up).  
He & his plank are secured to a horse.

The characters do the best job they can of tying up the
frost lizard, with ropes and chains.  In particular, his
neck is chained to his rear feet, so that if he awakens and
tries to freeze us, he'll never become a father (his head is
forced down and pointing under his body: it's a short chain!).
His left front&rear feet are chained together, similarly his
right two feet.  Also, we do the best we can of muzzling him
with a metal shield. 
The clairaudient flail (Blarimoor) person will ride near the
lizard and Sneedy, and listen for sounds of either
 awakening, at which time
Levi may have to sleep one again  (this will probably not be required).

The party mounts up, and Levi throws two tensor's floating disks
under the lizard, centered under him, side by side, and they
ride off toward town.  Note that in THIS group, only Levi and
Homy are visible (no others have been in meelee for a week or
more). Those two are visible only because of the spells they've
thrown.  Levi has 1 1st level spell left at this point, and
as mentioned earlier, it may be SLEEP (e.g.,if the lizard starts
boging out and attacking the party suddenly).  But we assume not,
that we get an hour or so toward town with disk still on and
lizard still asleep.  In that case, we simply plop the lizard down
in some suitable dense underbrush, and dismount to camoflage
the site even more (branches, etc.).  We mark a "B" on a tree
50' due south of the site, and continue on to town.

Once in town, we check Sneedy to see if he's still asleep
(probably will be), and if not then Levi blows his last spell
by CHARMing Sneedy, and commanding him to silence. Just to make
sure (in case he isn't really charmed), the two MU's will put some
live chickens in a cage on the plank alongside Sneedy
(in the village, surely there's a butcher or other store to
buy live poultry, hogs, etc.  If it's then too heavy for two
characters, two invisible ones will help them carry it, to
make it look much less loaded than it really is).
 or -- if no live squawking animal is to be had (unlikely), then
provisions from the saddlebags will go on the plank (along with the
bound and gagged Sneedy), and carry it up to their rooms (again
with two invisibles to make it look much lighter).
The idea is that the squawking will drown out any muffled moans.
If provisions must be used, then the MU's will be arguing as they
come into the inn, and keep arguing as they ascend the stairs
to their rooms.

If he's still sleeping when we hit town
(this is around 7:30 or 8:00), then
we take his body off the plank (still bound up and gagged),
and three invisible characters carry him up to the room
(so no one sees ANYTHING go by), and an hour later the two 
MU's go up to their rooms.  

We search his body carefully,
and an invisible character puts up the "We've got the goods"
notice for BG to read.  Sneedy is put in a room still blindfolded
and tied and gagged, and will not be fed or given water
(hope that BG turns up within a few days).
In no case will his blindfold or earplugs
or his bindings (hands feet, etc.)
be removed.  
At 6:00 the next day, assuming no BG, then we allow Sneedy
to wake up, but we throw two charms at him, and command him to
tell us the full story of his interactions with other cahracters.
We then re-gag him, and sleep him.
If possible, Levi and Homy will try to keep him perpetually
under sleep & charm both, unti BG arrives.

When BG comes, we will tell him about
the kllings, but not the burial, and about the presence of
Sneedy in the other room, and we will try to negotiate
for some heavy magic in exchange for a genuine live
frost lizard.  If we reach an agreement, he'll be told
about where the "B" tree is, the lizard's position, and
its invisible and bound-up state.  I also will then ask if
he's interested in future deals, e.g., when the new version
of the frost lizard comes out, in exchange for MORE magic.
If he refuses the first deal categorically, then I'll
tell hi about the lizard anyway, and will not propose that
second future-work deal.

If al this works:

  remove the Orc daggar from y possessions
  add HOMY's sleep spell points.
  add in Levy's sleep spell(s), + his invis. & tensor disks.
  let me know