This is really an inconvenience!
I live in Colorado Springs and have family in the Montrose area. All alternatives to US50 from Gunnison to Montrose add considerable inconvenience.
For me US160 and I70 are considerably out of the way. CO92 is mentioned as an alternative. It is a very poor alternative for RVs
. From the intersection with US50 at Blue Mesa Dam to Crawford CO92 narrow and twisty and much of it is pretty rough. It will shake up your RV. I have a family reunion in May. I will probably us CO92.
All of the interesting parts of Colorado are still accessible but a little bit more time will be required!