I did read about a guy who is a computer programmer. When he had a job at a big company that gave him his own office he lived in it. When he stayed late the boss just felt he was a dedicated worker. His job was temporary and so was the living in the office. Some people have lived on college campuses but not in a dormitory. They spent their nights huddled somewhere in small rooms in the library or a different school building. They used the shower in the gym. That is the only way to live indoors that is cheaper than renting a room, though always needing to buy restaurant food must add quite a bit of money to that lifestyle. It must be stressful to always be hiding. At least in a car or van all one needs to do is park in a neighborhood with apartment buildings and nobody will notice the strange car in the area. Tint the windows dark and put up customized sun shades in the front and rear windows for extra protection.
Living in any type of conventional vehicle or small RV requires simple living principals to be in place. It just wouldn't work if one bought things and didn't at the same time get rid of other things. For Christmas I'm buying a new laptop and a new exercise device. I'll be selling a larger desktop computer and a larger exercise device (if the new one is an improvement over the old one). For my birthday I bought a small pressure cooker to replace a much larger one. Since I don't have refrigerator space to store leftovers I must cook my meals one at a time. This is how I've adapted to a simpler living lifestyle.