More Housing Changes, Please

I'm in my mid fifties, planning for retirement. I find the current limit on the number of times I can change housing in the future to be just way too small, given that I'm planning for another forty years or so.

For example, my wife and I plan to sell our current house when I retire, and rent for a few years while we explore different areas of the country to possibly move to. After that, we'll buy a house, but we expect to downsize to a condo in our seventies, and to probably sell completely if we make it to our late eighties, in order to fund our remaining years (I know very few people in their nineties who have kept their house).

This seems like a very reasonable plan to me, but even kludging it up using a vacation residence leaves me one change short.