It should be possible. I see this as the exact same situation as http://www.getaround.com/, who are, according to techcrunch, "The Airbnb For Cars". They have a policy with Berkshire Hathaway that covers any damage to the rented cars.

You can write insurance for anything, if you're willing to pay enough premium. I can't imagine this premium would be that exorbitant for Airbnb to pay for it's users, just as Getaround does.