I live in Colorado Springs. I drive from Colorado Springs to Dallas area fairly frequently and I drive from Colorado Springs to Cheyenne as well.
One responder mentioned the route through Raton, NM. That is the way I go. However the is the only reasonable route for me. You have better options. If you drive US287 to Dumas then take US87 to Raton to get on I25 you will have to maneuver Raton Pass, the cities of Pueblo, Colorado Springs, Castle Rock, Denver and right by Fort Collins. Every one of them can hang you up in one way or another.
Click on this
MAP.
US287 is a four lane highway through Texas and 2 lane most of the rest of the way. It is a heavily used truck route but the road is generally well maintained. If you choose this route you will travel US287 from Fort Worth to Limon, CO where you will convert to CO71. CO71 is generally well maintained, is wide enough to drive comfortably in an RV and is mostly sparsely traveled. Pickup I80 just south of Kimball, NE and go west to Cheyenne.