I was perusingvandwellers.org earlier. The website has a gaudy color scheme that makes it hard to read, but I have to tell you, the content there is fascinating nonetheless.
Reading it, it occurred to me that the only technical obstacle between temporary and permanent living appears to be... a toilet! Everything else, you can find a solution around it.
There are a couple of options available, but none of them are very good:
For one, you can install RV toilets, but you still have to dispose of your own "dark water".
The alternative is to have access to public restroom facilities somehow, like using the bathroom at work, at a park, or having a gym membership. I think this is the most realistic, though imagine having to drive to the gym every time you need to take a dump.
Lastly, you can just "rough it" in the woods somewhere... but that's most likely illegal.
Anyways, that's my crazy observation for the day. That in the end, the majority of our housing cost actually goes into buying a connection to the municipal sewer system. Otherwise, a huge world of interesting and inexpensive alternative dwelling (not just RVs) open up to you.