For the past five years, the RV has just been driven around the campground. I don’t think the walls will fall apart while driving
Are there any soft spots in the floor ? Depending how level the rv was parked will determine how the water ran. Leaks don't always flow straight down. They can travel in any direction to find the lowest point.
I would be concerned about the tires. Anytime the salvage tow operators moved older rvs , the tires were the main problem.
Time and UV is the enemy causing sidewall cracks. Tires can also suffer internal damage over time where you can't see it. Many rv people change sneakers after 5 yrs or so, just to be safe. If your tires blow up at highway speed it won't matter much how soggy the sidewalls are.
I would also check the front end for worn parts. Check the frame as well for rust.