I skied Copper on those exact days last season (Thurs & Fri, not Saturday
: ), and it was fantastic. The entire front of the mountain was open, but it was too early for the bowls; they were closed. Although it wasn't "empty," lines were non-existant. As has been stated elsewhere, Copper is much better than the other Summit County areas.
That said... I'm sure that you're aware of the possible catastrophic season coming up for Colorado in 2002-2003. The only reason we had such good conditions last year was: lots of artificial snow... and barring a ridiculously wet fall, that ain't gonna be the case this year.
My unsolicited opinion: go to Utah.