Take a look at this RV that is built for motorcycles!
https://www.poprvs.com/conversion-semis-for-sale/international-38-in-mcclellan-park-california-164103
It is an International semi-truck converted to an RV so it has higher clearing for bumps or driveways and won't bottom out. It also has a powered liftgate and not just a storage area, but cabinets that allow you to work on your bikes. There is sleeping for eight if doubled up as there is a bunk above the driver, the two couches fold out and a bed in the bedroom.
This thing is built tough and rugged.