I’ve had some experience with living/traveling ultra-cheap (my hobby is rock climbing and I’ve known a few climbing “bums” over the years and have done some “dirtbagging” myself.)

Some things that I would recommend you consider:

Psychologically, it’s a lot easier to live on the cheap when you know you don’t really have to. I can sleep on the ground and eat little more than cliff bars for long stretches, but if I knew that was going to be “real life” forever, it would not be fun.

When you have kids, that changes things. Maybe you can do with less, but you will want them to have more.