Go with the tanks as they are, add some Stabil or some other brand fuel stabilizer to the tanks. You are using ethanol free gas to temper problems.
Pull the batteries, I would give them a charge about half-way through winter. If the stay in the boat and you are not charging, disconnect them.
After two recent battery failures-which I have never had in all the years I have been around them I have changed my approach with caveat that it might have been the quality of battery. I will find that out next spring.
Now others will probably disagree but those are my suggestions.