If you are looking for an alternative to skiing and avoiding the crowds, then maybe look at Nordic Skiing. The county has several options to get outdoors, but not have to be waiting in the lift lines. The local Nordic Centers have equipment to rent to make it hassle free. Here is a list of Nordic Centers in Summit County.
Gold Run Nordic Center is located on the north end of Breckenridge, near Highway 9 off Tiger Road at the Breckenridge Golf Course. Trails wind through the golf course and have a steeper, longer set of trails that head up into Gold Run Gulch.
Breckenridge Nordic Center is located on Ski Hill Road, before you reach the Breckenridge Ski Resort. Trails circle around the Shock Hill subdivision, Cucumber Gulch and also head to steeper trails to the north of the ski resort.
Frisco Nordic Center is right off Highway 9 on the south end of Frisco. This is large Nordic Center with great beginner terrain and easy trails, as well as lots of up and down that extend to Lake Dillon.
Keystone Nordic Center is nine miles of groomed trails in Keystone and you are able to access to 35 more ungroomed miles in the surrounding National Forest.
Copper Mountain Nordic Center offers free trails along the golf course and West Village.