I would assume everywhere will be swamped. Killington will surely be a busy time. However, if your friends need a little non-mountain distraction, Killington surely offers that!
I was at Placid a few years ago....Twas very busy. That being said, if it snows.....just avoid the major trails or just keep searching. There is a lot of mountain to enjoy at Killy. If your friends are ballsy, just go up to Jay.....or Maine!
Traveling the States and Taking Pictures