Many people have died in 20 mile per hour collisions. most all of them did not feel the need for seat belts.. NOTE Air Bags will not save your life without the help of seat belts and, well, have killed people. (Proven) it is my opinion they cause more injuries than they prevent.. (NOTE MY OPINION).
I have seen many photos of accidents involving motor homes since joining the assorted forums I belong to.. Most did a fairly good job of surving the crash. Better than many cars I've seen.
Some,, were .. Well, well destroyed,, but most of those took it broadside.
Short story: Met a young lady once, Full body cast (My sister was her hospital roomate) Chaplin came by to try and cheer her up (She needed it) he was trying to guess how she broke nearly every bone she had.. I told him he'd not believe it. He disagreed.
So he started asking questions: Skiing (no) Sky Diving (no) and I forget what all else.. Finally she gave me permission to tell him.....
She was sleeping in the back of a Winnie as they returned home from vacation and the driver of the Winnnie was busy goging through a GREEN (Please note GREEN) light when a Semi ran the red and climbed into bed with her.
Now, In a crash like that.. The Motor home stood exactly NO chance, neither would a car.
Home is where I park it!