I think sheltering in place is probably our best bet for Bad Things, Mark. OTOH, having three days of medicine, food, and water in the car (especially when one of us is diabetic and the other gets really grumpy when her sugars get low) could make the difference between inconvenience and an actual emergency. (And some really Bad Things might be much more bearable with clean underwear. Just sayin’.) So far we haven’t actually tested our ability to sleep in our car (Honda Fit — the back seats fold down nicely) and we probably won’t, since trying to move after sleeping in a car at our age would definitely be a Bad Thing.
Stay safe and dry, Mark!