Good heavens we are a negative bunch around here!
Do you think everyone moves out of the Southwest in the summer? (Well, I do, but I digress!) There are plenty of people out camping and RVing in the summer in the SW. That's why it's too crowded!
OP can manage just fine if he deals with the heat. He wants to use hookup parks -- i.e. run fans and an a/c when needed.
As long as he routes himself so he will be at higher elevations periodically I think he will be fine. We had a great time at Arches one July years ago, in a popup. Sure, it was hot!
