long term non-use/storage

I have health issues and have not used my Class B Xplorer230XL since last August. I filled the gas tank and added stabil. I winterized the water system and removed the house batteries. I just found out the starter battery is dead and not recoverable. I keep it in my driveway.

I may not be able to use it until mid 2021. Is there anything else I should do? I'm guessing I should remove the bad starter battery and either replace it or just leave it empty.