summarize a fifth wheel in Southwest Florida

I always summarize "fifth wheel" as "FW". :-) Actually, I'd do what I could to store in covered storage as the sun is fierce, even if the humidity may seem the worst of your issues. I'd certainly put a goodly quantity of RV antifreeze in the toilet and all the drains. I'd be sure to leave 5-10 gallons in the black tank to help keep any remaining solids half-way soft. Cover your tires, even if under cover. Park on boards to get the tires off the ground, too.

Lyle