You aren't going to get bountiful amounts of powder on the east coast but probably the best amount of snow there will be late december ish
They get about 375" per season, that's almost as much as Big Sky and Whistler. I went fist week January since they already had about 50" of snowfall since the beginning of December and were fully open (77 trails) but the east coast warmed up for 2-3 days and rained. Jay lost almost all of their terrain but 17-20 trails.
Check this out:
Jay Peak Promo 2008