+1 NRS Hydroskin sock, if your shoes are big enough...
... or since this is a one-time deal, cover your thick socks with a plastic bag before putting on your shoe. I find produce bags to be to thin. Bread bags work well. They are sturdy enough to get through a day, but not so tough that they roll your toes. (Your feet will slide around a bit in the shoes until things settle in.)
Expect to punch a hole with your big/longest toe. No big deal, a little damp won't hurt you. You'll still be warm. If you are concerned, take and extra set of bags and socks for the hike out.
Also, you want gaiters that have an instep strap/cord (Dirty Girls won't work) to maintain a tight fit to keep the snow from accumulating in you shoes.