On one Scenic cruise, the Rhône one.guest had a small - and he was quite a big man - mobility scooter which was plugged in every evening in the foyer. He navigated on board with two walking sticks, I was only aware of a few times that he needed crew assistance leaving or arriving on board. He and his wife one evening went ashore for dinner locally with French friends. Lovely guy he managed to join in most things and in Viviers he found the long way around to the organ recital in the cathedral. So it’s not impossible just takes a bit of - sounds wrong - get up and go.