If you can't find anyone to go with, here are some sites I use for bus trips.
Constant Contact EventSpot
Snowbirds Ski Tours >> Long Island Bus Trips >> January 2013
Browse our Ski Trips for Long Island, NY
None of them go to Jay Peak but Stratton, Okemo, Killington and Mount Snow are nice mountains. Mount Snow is ~3:30 hours from the city and has a good park.