Hwy 50 is a good road but there may still be a small construction area East of Cimarron. A very scenic drive!
There are several campgrounds and RV parks West of Gunnison, plus 4-5 in Gunnison. From Gunnison to Salida, there are a couple of FS campgrounds, plus two RV parks just west of Poncha Springs. Salida has a couple of RV parks, too.
Between Salida and Canon City there are 3-4 RV parks along the river, plus State campgrounds. There are a bunch of RV parks near Royal Gorge.
From there, you are almost to Pueblo.
For fuel, it's Montrose, Gunnison, and Salida area....none in between.
Have fun and enjoy the beautiful drive.