I would certainly look at the style of boats suggested by jsutter. They may be just the ticket. But I also know that a lot of older people actually like the minivans b/c they are easy. So I wonder if it isn’t that the Villager is too high to step up into.
If so, you might do a quick shop for some kind of add-on product, such as a flip down step or something like that. Many of these are fully modified to do wheel chairs. I’m sure that is very expensive but I’d be surprised if there weren’t reasonable “helper” types of products that could be easily installed.