RV insurance is very cheap in our state unless it's motorized/self propelled. We have always bought our RV's new and always paid cash for them for 55 years now, so financinng rules couldn't even require the RV to be insured. However, we do keep full coverage on all our RV's 12 months each year and always have.
We also have and exercise the option of calling our insurance agent and having just storage insurance on any one of our vehicles/tow vehicles when we don't plan to be using them for X time, like for instance when we are in Florida for our ~2-1/2 months each year. Costs nothing for us to do and saves us a lot of $$$ each year.