As I understand there are year round bouldering options around Boulder, I think Flagstaff is one of the main winter ones, along with Boulder Canyon. Hopefully someone will be able to give you a direct contact there, but The Spot was a dead friendly wall, and I don't think you'd struggle to find people to go out with.
Boulder is ridiculous, anaffluent town in stunning surroundings, not only home to some of the best climber in the US, but also the best skiers, road cyclist runners, etc, etc. You'll have a great time even if you don't get out climbing!