I don't think I've ever taken a sled back to the dealer
for the checkup. Of course, I usually have the sled
apart before it even sees first snow. 500 miles should
be no problem.
Check for any fluid leaks. Call your dealer to see if their
are any recalls needed. Give it a good inspection to
see if anything is melting due to pipe temps. Watch for
wires rubbing to become exposed. Grease. Check the
suspension for cracks. Check track tension. Check
belt deflection. Check chain tension.
I'm sure I'm forgetting things, but this is what I would
do.