If at all possible. plug the coach into shore power to keep the batteries charged. I have stored our coach without and, even when regularly using the gen to charge, the batteries still at some point will go dead. This happens because 1. you 'forgot' to visit coach and run generator. 2. You 'forgot' to add water. 3. You 'forgot' and left a storage compartment light on. . You 'forgot' to turn off the battery disconnect. 5. You 'forgot' that the inverter, even when switched off, still has a significant current draw. Just a few 'forgots'.
So I tried disconnecting the negative battery cable. Ok, no parasitic current draw, but because of the large capacitors in the inverter, sparks fly when you hook up that cable again. Just too many opportunities for failure.
Now that we have the one spot in the storage yard with shore power, I keep it plugged in and only have to keep an eye on the water level (1x / month).
I would count on your batteries failing, for one reason or other, if not plugged into shore power. Just my experience talking, you may do way better than me. For peace of mind, you might budget for a new set of batteries before you head out next spring. If you have success 'wintering over' your batteries, you'll be money ahead.
Cover your tires, clean w/soap and water and apply 303 Protectant every so often. Keep 'em aired up too. Cycle the slideouts, and watch out for rodents! (or scorpions in AZ!)