You will probably get through at least one night without running the genny to keep the fridge up. Assuming you still have the original AGM's, just don't go below 50% charge.
Our last boondocking adventure was around the corner from you in the Smokeys at Smokemont last fall. All the shade was a savior, but we still had to run the genny 2 hrs. in the AM and 2 Hrs. at night before they closed down the generator hours to get the batteries back up.
You're like me with the tires. I did change out the front steer tires to Toyos and have been pleased with not just the lower cost, but we found the ride so much better than the Michelins. I plan on buying 4 rear drive Toyos after our trip to the west coast.
The Toyos I went with are M154 265/75 22.5. Can't say enough good about them so will stick with them when I do the rears. They are unbelievably close in size to the Michelins and generally folks speak highly of the Toyos on these forums.
2 safety modifications I added were the Safe T Plus steering damper (maybe yours already has it?) and the Tyron Tire system on the front wheels. A front blow out is my biggest nightmare and I want some level of peace of mind? Been through rear blow outs on a class A dually before and other than being startling I found it manageable. I just don't feel that way about the front steer tire blow outs though. The Safety T Plus also improved handling quite a bit and I don't have to work the wheel as much as when we got it out of the factory.
Another "no cost" and easy modification that greatly improves F53 handling is called the Cheap Handling Fix, which may have already been done to your rig. The link to it is here if it has not yet been done to the rig.
Well didn't mean to ramble so much. Hopefully we'll see each other at an RV park someday and share war stories about our respective rigs! Holler here if you need anything!
All the best and safe travels. Joe