Not yet, just going to our place a little north of Harrison. But Wednesday we're planning to head for the UP for 10 days or so. I hope the a/c in the truck camper works.

But we may not need it. We took the truck camper to the UP 3 summers ago and never needed it, it cooled down so nicely at night. I prefer to just have the windows open and be able to hear the night nature sounds or the low rumble of a freighter going past the campground at the Soo. Much nicer than the drone of the a/c, but it's good to have it if we need it. So much nicer to sleep when it's cool.
Yes, the humidity is really hard to handle. It just seems to sap your strength, at least it does for me. I don't mind hot weather, if the humidity is down. But when the heat is high and humidity is high too it can be pretty miserable.