We've done that heat a couple times, but without pets and with full hook-ups.
On the rare occasion that we do camp in that heat, we get the RV cooled down with AC & generator before we leave home, and don't turn it off until we're plugging in at a campground.
Will dual AC units & good insulation in our DP, we still see temps of 90+ inside the RV at the heat of the day. The Dometic rep I spoke to once explained that these units were only designed to reduced the inside temp by 20 degrees, no more. So when it's 110+ degrees outside, you can't expect them to maintain any better than 90+ inside.
And if you turn them off and let it heat up inside, forget it. You won't get it back down for many hours.
I wouldn't even consider camping in that heat without FHU.
And if you're going to try it, bring good window shades, preferrably the reflective ones. I lined the windshield and all of the large windows with the reflective shades, and it made a significant difference. I think we kept it down to near 80 degrees inside with FHU when it was 110-115 outside.
