I have spent some time in Pagosa Springs. Small town atmosphere, a bit of shopping and eating (Fantastic Mexican) FANTASTIC hot springs, went in March a couple of years ago and also did some skiing and snowmobiling. The snowmobiling was the most fun I have had since ... well, a long time. Also took a nice day trip to Durango.
Also have spent time in Steamboat Springs. Another FANTASTIC hot spring and good eating and so on. Fort Collins is a great town and you could always spend an afternoon at the New Belgium Brewery. Cannot go wrong there, if you like that sort of thing.
Colorado is beautiful year round but keep in mind the time I spent in Colorado was before owning an Airstream so I cannot speak to the campgrounds.
Either way, have fun.
If I only had a dollar for every time I got distracted, I wish I had a puppy.