re: Ski trip options

Whistler/Blackcomb is great. However, believe it or not, even January can at times be dodgy in terms of conditions. Late January, sure. Early January, I would look elsewhere. Don't forget, you will need to fly into Vancouver and drive/bus to Whistler. If it is a week-long trip in late January, you cannot do much better than Whistler.

Telluride is fantastic but the best terrain is challenging. The town is really, really cool. Telluride is often one of my first choices because of the challenging terrain, cool town, and small(er) crowds.

I'd skip Breck and Copper - not my favorites.

I hate to recommend it, but Beaver Creek could be a great choice if you are looking for a short(er) trip. You may have missed your window to book for anything near a reasonable price. Before, I've stayed at the Osprey, and the ski-in/ski-out option is truly unbelievable (closest hotel to a lift in North America). Beaver Creek, as a mountain, has great intermediate terrain, and really nice grooming. Also, great restaurant experiences. I typically try to avoid Beaver Creek (first, because of the terrain; second, the price). But for an intermediate skier, there are not many options that are better.

Unfortunately, I haven't been to Big Sky so cannot comment.