Wow! I appreciate everyone's suggestions and willingness to help us work through this. When I told her yesterday about what I am trying to work out, she was very excited about it.
I think I'm going to have to give up on our current RV. There is just so little room to carry everything she requires at this point. I looked at The Winnebago website and really liked what they are doing for access enabled RVs. At this point, I don't know what the costs would be and I assume that to add handicap access is expensive on a new rig. I also know WB likes to steer you to their dealers but I don't think that most dealers would know much about ordering an access RV. I have looked at the used market and there isn't a lot available right now, probably because we are in the heart of the summer camping season. It will probably be our best option.
I also considered toy haulers. It would have to be a bumper pull as we need an access van for my wife to travel in. She wouldn't be able to very easily get up into a large pick-up. That would mean besides buying a trailer, we'd have to sell our Sienna access van and get something bigger like an E450 van which could prove to be costly on top of the price of the new TT.
I really appreciate everyone's help and suggestions especially those that had resources to suggest. At this point, I think I might try to sell our RV and plan on looking for a nice used accessible unit. Maybe we can get one in time to enjoy some of the late Indian summer we enjoy here in the Great Northwet.