I would never drop collision libility insurance any time, unless you can affort a cash loss.
14 years ago we loss our 1982 Blue Bird Wander Lodge while camping and we where not at the site until later. It was a total loss. We had State Farm at the time and they were very good and wrote a check for the total amount we paid for it + sales tax. We also loss all of our personal property (had to go to WalMart that night for clothes to wear)
RV insurance doesn't cover your personal effects! Your home owners insurance covers personal libility & effects/property. Luckly we had full replacement value on our house insurance. State Farm paid $7,000 of a $11,000 loss on our personal items.
Our homer owners insurance came to our resque, when we were sued for our horse kicking a sue happy person, insurance company lawyers won, saving us over $100,000.00 and our only cost has been the yearly insurance premium.
We carry the max liability home & auto.
Many more things factor into insurance then basic costs and comparisions, I was lucky to have good insurance agents!
How many have people have heard the story about the motorhome couple, who's tow car blew a tire while traveling across Montana sereral years ago? FMAC had a very enlighting article about this accident.