Without power available, the parasitic loads may drain the batteries in a few weeks.
Fill the fuel tank to the top and add three times the normal amount of Stabil. Run the generator to circulate the Stabil through the generator engine.
Wash the coach with one of the wash/wax products, including the roof. Make sure that all roof seams are sealed to guard against leaks. Running the engine is not a problem if you let it warm up but if you have access, why not take it for a short ride which will help all systems and help the tires also? If you can't take the vehicle out, at least pull forward and back it up, stopping with the tires in a different position.
With the constant winds in Florida, any cover will eventually wear through the paint on the corners. A year of outside storage is no problem at all in Florida.
There are stations around here that sell non-ethanol gasoline, but I would still use triple Stabil. Do NOT use AV gas. It is 100LL(100 octane LOW LEAD) and it may do a number on your catalytic converter that is not designed for leaded fuel.