how about a 4-year long cruise?
I didn't include the link from your post, since anyone who wants to can view it.
But about cruising, and/or retiring to someplace outside the U.S. :
I visited Canada briefly a few times, with family and co-workers, before you needed a passport to do that. Back in 2000, I flew to Europe (and visited for two-and-a-half weeks): I spent most of my time in the Irish Republic, about 3 days in England (one night in the Stonehenge area, the rest in London), and a day in Wales (Cardiff). On the way back, I spent a day in the Netherlands (Amsterdam). I absolutely loved it- visiting sites and buildings where many of my ancestors lived before most Europeans knew about the Americas. And the people were terrific.
I cruised back to the U.S.; it was more expensive than flying, but enjoyable; I'd never flown before, and if it had turned out flying scared me, I wouldn't be worrying about the flight back home. The cruise was fun, but I think anything much more than a week on a ship (the time it took to cruise back to the States) would get boring.
But I still think I would rather live the rest of my life here in the U.S. I'd also feel beyond awkward on such a long tour, constantly visiting countries where I didn't know the language.