Colorado is not like Wisconson necessarily. The majority of the time the roads are dry. If it storms, they typically thaw within a few days of sun after the plows do their thing. You just have to work around the weather.
As far as size, you are no bigger than all the shuttles and tour buses that travel into the same places continuously over the winter.
Cold - you bet. Your RV may be 4 season but the Colorado cold will put you to the test. Research how to keep pipes and tubing from freezing - expect to use a lot of propane, which is not always easy to find in resort town.
Understand the new CO laws on chains. For most of the winter, you will have to always have them available, and when declared active you can be fined heavily if you are the source of a road closure because you didn't chain up. Colorado has been aggressive in installing chain up lanes off the road that give you a wide berth to chain up. They are well lit and safe, but you will have to share with truckers. This may provide some info
Colorado non-commercial chain laws
