Did something like this upon graduation from University. Threw a bunch of stuff in the back of a station wagon - anyone remember those? - and drove 4000 miles in less than 10 days, sleeping in the back. Now-of-days, no way. I w*rked hard to save enough to stay in mid-level motels as I travel.
Biggest issue I would see (in the what could possibly go wrong department) - break ins. Here in paradise, leaving ANYTHING visible (and sometimes not visible) invites a smash and grab. I've pulled into "scenic" points and seen broken side-glass debris from as many as 3 cars in a row. Hopefully, staying in "camping" areas leads to less of this behavior but it could really mess up your travel momentum - just fixing a window. A loaded, unattended car just might attract a break-in. Contingency plans are in order unless you always park in the right places. It seems to be a different world than when I did this 50 years ago. YMMV