They clear the MUPS in the Parker area about as fast as they clear the roads. They would be generally rideable, if you look out for patches of snow and ice, especially in the shade areas of bridge underpasses.
Historically, the snow doesn't "stay" all winter, but melts and then snows again. However, last year was an exception, and this year may be also.
Certainly there are lots of places where one may take a decent walk. Cross country skiing is problematic most of the time, due to the generally rapid snow melt and plowed trails. Generally, there may be places in the state parks where one might XC ski (if there is enough snow) - Chatfield and Cherry Creek are both at about 5,000 acres.