I think that would depend on what coverage the Rental company provides and do you consider it adequate coverage. Often the rental coverage benefits the company not the renter so check it out carefully.
I don't like to have a gap between coverages either!
Yours is probably a good question to ask your regular insurance agent.
I've only rented an RV once, and instead of buying the rental outfit's coverage I had my own company provide insurance as a "rider" on my regular auto policy.
It didn't cost that much, and I had the peace of mind of knowing that I (and my other assets) was/were seamlessly protected against all eventualities.
" Not every mind that wanders is lost. " With apologies toJ.R.R. Tolkien
The insurance cost is included in the rental fee. I am wondering move about roadside assistance I guess. What if the motorhome doesnt start because of dead battery, or perhaps I get a flat tire somewhere.