First, when does the ski season usually open and when does it actually start to get good? Second, I know there are a lot of options to ski in Colorado.
"High resorts" e.g. Loveland, A Basin - get open in November (although I think we had Halloween skiing recently) There's great early season skiing in December and January. Prime season is usually Feb-Apr
Skiing is always *good* -- it's what you make of it. The better the snow, the bigger the crowds.
There are LOTS of alternatives to skiing in Summit County (e.g. Breckenridge, Copper Mountain, etc.) Try Monarch Mountain or Ski Cooper for more "family friendly" venues with virtually no chance of waiting in a lift line. Also, El Dora is a nice, easy access ski area near Boulder, CO. Loveland has some of the highest terrain (and it's beautiful up there) but you'll still deal with the traffic on I-70 if you're staying in the Denver metro area.
Last -- find the "Colorado Gems" card for discounts at Colorado ski resorts. It's a bargain for all the free and discounted stuff you get. I think they are $10.