Since you are rethinking the idea of the southern route, are you thinking of using I-70 in either direction? If so, you will be traveling through Colorado, where altitude = cooler temperatures.
And, as mentioned, get off I-70 in Colorado and travel some "back roads," which are major travel routes for those of us who live in Colorado. For more info on some of those back roads, see my Colorado RV camping blog at https://2fanrgs.blogspot.com. (Sorry it is not a click link, but I forgot to start this on the Advanced Post Form).
