I have noticed that my class c MH does not get any warmer than the outside temperature if I close the shades on the south and west sides and open the skylight vents. They are not like cars that quickly heat up if in the sun.. I suppose that is due to the windows being perpendicular to the ground instead slanted to catch the sun's rays and the cab-over shaded windshield.
I only worry about the pets left inside when outdoor temps get above 90. And I try to stay where the climate is milder. I'm now a fair weather friend. I plan my travels around the seasons so I can avoid climate extremes whenever possible. Such is the joy of retirement
Also, if you do use your generator for heating/cooling while away, make sure you have plenty of fuel. My gennie will shut down when the gas tank is less than 1/4 full.