Go 50/50 with your clothes. I have worn nothing but shorts for the last 2 weeks. Most on the mtn, other than serious gapers/tourons, have just snow pants and tank tops or tshirts. It feels 60 in the day and probably mid 30s a night.. I rode my bike home at 11pm las night doing 40mph downhill and didn't get cold. I had on a shell and shorts. There were quite a few people boarding and skiing in shorts yesterday too.
I don't hang out in silverthorn ever so I don't know where to go there. If your woman is with you they have a decent outlet mall there and sales are on right now.... They may chill for that Easter week though with all the mexicans in the area.