i've been living out of a van for about 8 years and never had a problem. people for the most part don't care about your individual situation. they just have to enter data into a box and click next for the whole system to work. so here is what i did in the beginning, and what i do now.
i rented a place to stay, and then when i set up my drivers license i used a mailing address instead of my actual address. so all mail went to a po box. everytime i had to deal with the anyone i just put in the same info even though i had only rented the place for a couple of months. sign up for insurance online, use your po box as your home address, or the address where the car is stored. they could easily go to google maps and find out it is just a po box, but they dont. because they done care, they are just putting data into boxes and doing the minimum amount of work required for their job.
my most recent version of this is i bought some remote land, where there is no mail delivery. so i have to use a po box. the land was cheap, and there is nothing there even if you could find it (which you cant because there are no road signs or printed addresses out there). my drivers license had the address of my land, i use a po box, because there is no mail delivery, and i have paper work proving that i own property.
dont make a claim, insurance is a scam. drive carefully, and save money to cover your expenses, or unexpected problems. having insurance is just another piece of paper to make you look legit,.