I know what the problem you have with needing to go when you can go. You don't have any choice. Those are the weeks you're given and it doesn't matter how big the crowds are or how low the snow cover is, that's the only time you have.
How about trying something really outside the box? This is an example based on my own local knowledge. You could change this to fit any locale that you might find that you want to try.
First assumption: Everything is crowded at that time.
Second: Snow cover is low in many areas.
Third (a big one): You don't mind driving a bit.
Fourth: The Pacific coast areas will have the best coverage at that time.
OK, If Whistler is too expensive and crowded, you could decide to tour a region. Take mine for instance; the Washington Cascades. Start in Seattle, rent a vehicle (4WD would be nice), and head for the hills. While the ski areas in Washington are not "resorts" because they don't have lodging, they are all close to urban areas and you can get lodging close and drive to the hill relatively easily. You could make it a bit of a road trip. I would follow a path that would go north to south, or the opposite, doesn't really matter.
Here it is:
Get your vehicle and drive to Bellingham from Seattle, head into the hills and stay in Glacier at one of the places that are for rent there, if nothing is available, stay in B'ham at Motel 6. Spend two days at Mt. Baker, then hit the road.
2.5 hours south is Stevens Pass. Get a room in one of the small towns along Highway 2. Gold Bar would be a good choice, though Skykomish would be best. Spend one or two days at Stevens and then head for Mission Ridge, east of Stevens near Wenatchee.
Mission might be a problem at that time of year, it isn't coastal so it may not have enough snow. Bring rock skis if it looks marginal. The rocks there are the worst I've ever seen. You could shave with them. The skiing is fun, though. Not real steep or challenging, but there is interesting terrain and a great vibe. It's the best chance you'll have of having sunny weather. Ski here one day. Stay in Wenatchee.
Head for Yakima, get a room. While you're here it's the weekend, take a break and do a winery tour. Some of America's best wines come from the Yakima valley. You'll be missing the massive Chistmas break weekend crowds at the ski areas, resting your legs, and enjoying some great wine.
On Monday pack up and go to White Pass. This is another small area with a local feel. Not too challenging, but the Mahre brothers came from there, so it can't be all bad. Spend one day.
Crossing over to the wet side of the range again take a long drive around Mt. Rainier (the direct route is closed in the winter) and go to Crystal Mountain. Try to arrange on-mountain lodging. This is the closest WA comes to a destination area. The only reason it isn't a big name is that lodging is restricted in size, so not many out-of-towners can stay on the hill.
Crystal surprises people because it's bigger and knarlier than they imagine it will be. This area is worth several days. When you're ready to leave, SeaTac airport is only about 1.5 hours away.
While it was fun making up this ininerary, you could probably do this kind of trip in Oregon or California as well, I just don't know them well enough to tell you much. Have a great time wherever you go.