I just got back from a 15 week trip out West. Wouldn't ever consider a pet.
When I was at the parks, I was usually gone 6-10 hours per day. Can't take them on trails and can't leave them in an RV without AC. Most NP camping areas do NOT have electrical hookups. Plus, when I had electricity, I never wanted to leave the AC on when I was not there and never did, no matter what the temperature. I don't believe in wasting that much electricity.
One private park had a sign saying There would be additional charges if the AC was on and no one home.