Depends on the location but living without a job is not really feasible without government assistance of some sort which is usually tied to stress and extra work proving you need the money. For example in many US states you have to prove that you are constantly looking for a new job and are willing to accept any kind of job offered in order to receive unemployment assistance. This is a far cry from being relaxed enough to work on projects in peace.
Have you heard of the 4% rule? That basically means if you save up X amount, you can spend 4% of X every year, in perpetuity, given some reasonable return like 7%. So if you can live on $80k/year, save and invest $2 million.
I can live on much less than $80k and I actually currently do. But $2 million actually sounds like a reasonable goal. If I can get it down to $1 million then that will be achievable.
Yes, if you can get your expenses under 40K a year, you'll be good. I read a lot of financial independence / FIRE forums. Some people are much more conservative and think 4% is too high. They prefer the 3.5% or even 3% rule. For a very early, longer retirement, they are probably right. The 4% rule was based on a "normal" 30 year retirement.
