I think that the cheap “tiny homes” that I've seen volunteers build for the homeless have a lot of merit. Of course you still have the land-use issues.
In the Seattle area they have “tent cities” that will spend a few months on a church property, and then go to another property. They are self governed and no increase in crime or other stuff. Very strict on alcohol and drug use. We used to go and make meals (we would buy the supplies, cook and serve the people). Many were just temporarily down on their luck and could use the hand up.
Although one guy I spoke with, and one of the main leaders of the camp, told me he didn't have to be homeless - he didn't want to work because then he would have to pay taxes for things he didn't agree with! (obama years too.) “Well, I'm guessing nobody agrees with everything the government spends our money on. Like me paying for people like you that just chose not to work!”
We quit helping out after that.
Yes, I think the tiny homes have great appeal and serve a good purpose.
Perhaps one day your childhood dreams/boat plans will become a reality. Sounds like it has deep roots in you, going DOWN the Mississippi!