I regularly travel from Fairplay to Pagosa Springs, which is mostly a pretty easy tow. Wolf Creek Pass on 160 is demanding, both up and down. A good engine brake comes in pretty handy going down the west side of the pass. You must keep your speed under control and brakes alone won't do the job. Once you get down the hill, 160 to Durango is easy.
I don't know about 285 from Denver to Fairplay.