I am in a similar situation and while still healthy, I am looking for "simple and easy". As you can see we have a Fleetwood Expedition and tow a Jeep Liberty. We love this setup, but would prefer to not tow and have an rv the DW feels comfortable driving. Based upon our needs/preferences this means a Mercedes Sprinter in the A or C/B+ model. After you have read all the replies, done your research and visited dealers, you should be able to narrow down what length, width, floorplan, and tow/not tow you need. We have spent months looking at the options and the Thor ACE was one we looked at, but we decided that the 25' length and 90" width of the Sprinter was what we wanted. There are also some nice B+/Cs out there in the 25 to 30' range that even have 3 slides. In our situation we shall probably not tow for most of our trips, but with the Sprinter, we have the option to tow if required.
We defined downsizing as the Sprinter based rvs, but you need to decide what is the right length, width and floorplan for your interior comfort/storage and exterior comfort/storage. Good luck.