I grew up 30 minutes from Tremblant and now live an hour away. DO NOT GO TO TREMBLANT IN DECEMEBER! YOU WILL WASTE YOUR $$$$. Tremblant is losing money hand over fist. They will not run anything beyond the absolute minimum number of lifts before xmas. Even if they get snow, they will not open very much terrain, they will save it for the Xmas holidays. Toss in the fact that all of the employees are currently threatening a strike, and you have a poor situation for a ski week. (Don't laugh, the employees actually did go on strike a few years ago over the XMAS holidays and the hill was shut down for a week during the busiest time of year). The place is an over priced joke. Hey, if you want to go hang out in a ski village, be seen in a Spyder Ski Suit drinking and eating, then heck, go for it. If you want to actually ski, avoid it at all costs. Oh yeah, they have not really been doing maintenance on the lifts, so there is a chance they run into uphill capacity issues; two springs ago I got stuck on the south side of the mountain on a busy day and the Gondola broke down (Again!). The line up for the only other lift open was over an hour long. That is not an uncommon occurence there.
The best skiing will be at Le Massif, but there is no on site lodging. Your best bet is to rent a condo or hotel at the base of Mont Ste Anne. This would allow you to ski Ste Anne as well as Le massif. I guess it is about a 40 minute drive from Ste Anne to Le massif. Heck, I personally would rent a condo at Ste Anne, and just ski Massif every day, IT IS THAT GOOD! Scenery is phenomenal, great people working there, you will be made to feel welcome, and the hill is great. Glades, bumps, cruisers, a good mix of intermediate and expert terrain. You cannot go wrong. And they have already been getting snow.Tremblant is still bare.
The other option is to stay in Quebec city, which is a great tourist town. It is about 20 mins to Ste Anne and an hour to le massif.
Just my .02.