We would take my Dad with us on our RV trips. He was in a wheelchair so I equipped our 5th wheel with a lift that would allow me to get him inside of the RV through the door. I had to use one of the narrow transport type wheelchairs so it would fit through the door. Once inside he could be transferred from the wheelchair to the sofa. We used an over sized TV Tray for his food. A bedside commode was used next to the sofa. The sofa is deep enough to use as a single bed without the need to open up the sofa sleeper. I was able to move him from sofa to wheelchair to commode without the need for a Hoyer lift.
I did use a Hoyer lift to get him from the wheelchair in and out of our truck we used to tow the 5th wheel. He really enjoyed the trips.
Now my DW is beginning to have mobility issues so we are considering a new RV and I believe the best choice would be a ToyHauler type either bumper tow, 5th wheel or MH with a ramp at the rear. The ramp would allow her to enter or exit using her mobility scooter. The garage area can be customized to meet her needs for sleeping and bathroom.
Good luck in your search, hope you find the right combination. I truly believe getting out of the house and into a different environment and scenery really helps their well being.