When I looked into this I came down on using the auto carrier for the camper. So I've got liability, comp & collision for just over $100. RV insurers wanted hundreds. As I've had only two very small claims in over 50 years of driving, home ownership, etc., I've saved thousands by not overinsuring. Enough to swallow some loss without regret. Downside to using the auto insurance, content not included. I would have to look to my homeowners. So with my $2k deductible I really don't have content coverage. Upside, it was suggested that I cancel liability when the rig is parked, saving a bit more. I haven't done that yet with Hartford but did in the past with Safeco.
A little off topic, I recently shopped USAA and my quote for apples and apples was nearly double Hartford. I can only guess as to the reason. They look at your credit and I have mine locked with all three reporting agencies, so they didn't get a report.