The Beave can be pretty good for finding some untracked if you know how to ferret it out. The only caveat I'll give is that it's at a lower elevation than the Summit county spots, therefore warmer. If temps have stayed cold, in January it should, it'll be a good choice. If for some reason it's been getting well above freezing in Summit for a few days, it's probably going to be less than ideal conditions at the Beaver.
Winterpark (Mary Jane), Loveland, Beaver Creek, and Vail are probably the best spots for finding some untracked if it hasn't snowed in awhile. More than a week out and it's going to be pretty tough to find good snow anywhere except the backcountry.