Heres 4 options right off Peak-to-Peak Hwy between Nederland and Lyons. I am more than open to other suggestions, these are just some options that aren’t that far from me or JP
1st map is Gold Hill/North end of Switzerland trailStart with hill climb off Sawmill road (south west facing) then decsends onto far north Switzerland trail - goes to Cliffhanger 2.0, steep and rocky hill climb that will be pretty difficult with the snow
2nd map is Gordon Gulch and various trails that lead to the southwestern most part of Switzerland trail. Mostly easy except one spur that will be very difficult with snow
3rd map shows Dry St Vrain in upper right - aka Big John Mountain. Easy trail system but rarely visited and with snow could be challenging. Short so could include with the other trail shown, Miller Rock. This would be the most difficult as it starts out with a fairly steep climb on a North facing trail that is not travelled often..... with the snow this would be very challenging but also could be fun