I'm writing from the UK, where living on the road is hard due to legals and climate. But if I lived in a high rent area of the US, I'd definitely look into getting a nice RV.

In a city, this would at first seem impractical. But if you cut back to a much smaller vehicle, there is generally safe free parking to be found at night. Especially if your friend has an apartment, but doesn't use the parking. Gym membership for showers, kitchen at work, maybe a games room. You really only need a box to live in most days.

This would let you pull in high wages, living low and gathering savings, then retire to the country to bootstrap your amazing SaaS business.

Oh fantasy.

Back in reality, I currently rent a bedroom from a fairly rich family. Especially during the winter, I save a huge amount on bills. The only problem is the lack of private space, but temporarily that's fine.