There's another aspect to this: the color of the RV. Both our Class C and our 5er were your basic "white boxes" - and they tended to remain cooler than the ambient temp. If it was under 85 or so, we'd simply leave the fantastic fan running; plus a large battery-operated fan pointed at the couch where the dogs slept. I mean, they sleep on our deck in the ambient heat for hours....LOL! But if it was truly hot and humid, we'd fire the genny on the Class C and turn on the A/C - and then would check in frequently. (The 5er only got used during winter)
Nowadays, many RVs are full-body paint, and the tendency is towards dark colors. If I owned one of those beauties - I'd have the genny and A/C running for sure. Because I doubt the relatively thin insulation of an RV can hold off the heatup effect of a dark color for very long....