I've lived in a van for months at a time, even took sponge baths, with a solar shower "bag" being heated atop the van, standing in an inflatable kids wading pool, altho had to hunch over pretty badly. :-) i've also lived out of a backpack for weeks at a time, and one 2 week period, it was cold, rainy, sometimes snow at night. It can be done, if you are determined and knowledgable, altho some high $ gear helps a lot with comfort-safety, you can scrounge stuff to suffice, then leave it without much fear anyolne will steal it. The only reasons not to work up to a FUNCTIONAL van in 3-4 weeks are dope, booze, or mental issues.