We snowbird so we're out longer in a larger loop. We have left Michigan in the beginning of Sept and headed up to U. P. and across to Lake Itasca headwaters of the Mississippi then over to the Badlands, Black Hills, Denver(some ac) and Moab around Oct 15(some ac/some furnace). Stayed there two weeks and headed for Goblin Valley, North St George area, Overton Nv, Ft Mohave, Parker, Bouse, Quartszite, Yuma, Houston and back up in the spring.
We hit Yuma/Socal end of Nov beginning of Dec and weather is great. We have been in Cottonwood/Sedona aroud Nov 1 to 8th then hit Congress until 25th of Nov.
Then Quartzsite 22nd Of Nov
Ogilby Rd Socal Dec 13th. then back up to the Q on Jan 11th.
On 19th Jan headed toward Houston. Stayed in Casa Grande 2 days then Escapees Benson 3 days then Junction Tx 2 days and then in to Houston.
Sort of helterskelter how I wrote it but you get the idea. We travel with the intention of not having it too hot. We'd rather be a little too cool but have had to run the generator a few times during the afternoon. We always shoot for boondocking and then places like Escapees and seldon pay for a full campground. When we have paid for a campground in places like Moab it's about $45+ per night.
We have stayed in Moab until the end of Oct and my son returned to Denver to see snow days later.
One year in Black Hills/Wall area we ran the ac a lot around mid Sept.
If you stayed out 3 months you may want to be dipping back down into Tx Ar Tenn etc.
2017 we stayed in Houston area until end of April and were running the ac all the time.
DW was telling me all sorts of dates as I was typing, hope it gives you an idea of fall travel.