I know that a number of people do come up for Chinese New Year but in my experience, it's not extra busy then. It's nothing like Christmas or spring break. However, this year the new year starts on what is Family Day in BC, so expect that weekend to be crowded.
There are a number of ski in/out hotels in Whistler Village, Upper Village and Creekside. If you look at Whistler's website you'll see accommodation maps. Whistler Village is the center of the action, so if that's important choose a hotel there.