New Year's day at Breck was awesome. No crowds(virtually empty), and it snowed all day. I even caught some nice runs at Keystone that night too. The crowds on the surrounding days were high, but once you get higher on the mountains and avoid the lower lifts, you're usually fine.
Plus, I usually go up for a few days around the holidays so I get in plenty of riding, but I also get to hang out with family and friends. The past few years we've rented condos large enough to sleep 10-12 comfortably, but actually about 25-30 show up. We always have hot tubs there too. It's not always about the mountain. I have my pass, so if I only take a few runs that day, it doesn't bother me, there's plenty of other times I'll go. I don't feel like I'm wasting money.
Short of opening days, I've rarely had times when the crowds have been a significant deterrent. Only time I can actually remember leaving due to the lift lines was a few years back. I think I was at Breck then as well on opening day and I waited in the lift line about 45mins, took a single crappy run, waited another 45mins, came back down saw the long line again and decided to have a few beers and watch football. After that, we left. 45mins. for a 3-5 minute ride down the hill is no fun, hence why I mentioned putting off the Thanksgiving trip a few weeks. The snow may not be there by then.
This 1st pic is from New Year's Eve. That was about the longest lift line I saw all day, I avoided the base lifts like the plague.

This 2nd pic was mainly just to show the snow on New Year's Day, I don't have any pics showing crowds that day, but honestly, they were non-existent.

I know these are anecdotal at best, but I know I had a hell of a good time and I try to make it up every year that I can, if nothing else than to have a mini family reunion with a few days of riding thrown in.