Also, re: the amount of money - you're absolutely right. 5m at the 4% safe withdrawal rate is 200k a year which would be way more than enough. I'll start the bidding at 2.5m for those aformementioned tech billionaires (what a steal! this deal won't last! act fast!)
One article I really like from that blog is this one: https://www.mrmoneymustache.com/2015/08/19/urban-tribe/
It's more than a little bit counter to the idea of "fucking off from society to the woods", though. Still, a man can dream of total independence :)