If you are in Pagosa Springs area you might consider going over to Bayfield, turn north to the Vallecito Lake area and go on up almost to the Wilderness Area boundary and stay at Blue Spruce RV Park. We spent four days there a couple of weeks ago and had to use heat in the mornings.
The only thing, don't go without reservations. They stay pretty full. Call ahead before making that long drive from Bayfield.
As for Gunnison, there are several good campgrounds there. In recent years we have been staying at Tall Texan on the road up to Crested Butte. And there is a relatively new park in Crested Butte--expensive and no sewer and no dumping station. It is a great place to stay even with those limitations.