I don't think your likely to find a NP CG that takes RV's that bans generators. They all have generator hours but they allow their use. Typical hours are 8 AM to 6 PM possibly with a break in the middle.
Likewise you aren't going to find a small secluded CG that takes RV's in RMNP. They range from 50 to 250 sites per CG. I would strongly advise getting reservations no later than January. It's not as bad as Yellowstone or Yosemite but they do fill up fast especially for popular periods.
Go to the park's site:
RMNP CG and they describe the available CG.