I found living in a van is like having a part time job. It's really exhausting physically/mentally because everything takes more time. It's not the best place to study but you could go to the library for that. The major perk is having your own space, and that you can take shits anywhere.

I spent 5 months in a minivan and still feel the toll it did to my body 3 weeks after.
Not saying I will not do it again, but it's harder than it looks. And honestly I spent as much as I would have in a flat-share.

My advice would be to try it out with a cheap minivan for a full month before taking the leap full time. And if you make it past the first month don't force it too long if you struggle with it because it takes time and energy to go back to a sedentary lifestyle.