Early season skiing rewards two things, snowmaking power and base altitude, so lead with those. Keystone and Copper win on snowmaking and a willingness to open the instant it turns cold, which is why they are reliably first. Breckenridge and the other high resorts win on elevation, keeping whatever falls cold and skiable. In November you are choosing certainty, not variety, so favor the mountains built to open early.
Set your expectations for terrain honestly. Early in the season only a fraction of any mountain is open, usually top to mid groomed runs served by the main lifts, with bowls and steeps coming later. This is fine for cruising, families and rust shaking laps, and it is genuinely quiet and good value before the holiday crowds arrive. It is not the trip for an expert chasing big off piste lines.
Match the base to what you want around the skiing. Breckenridge and Aspen are in full swing early with the best dining and comfort, Beaver Creek and Vail deliver polished service, and Monarch strips it to snow and savings. For the wider picture, compare our early season in the United States ranking and early season in the Alps, browse the best ski resorts in Colorado, and plan from the United States destination guide.