In the car? That makes a whole lot of sense to me. It would seem to be one of those no-brainer survival tactics.
I had a long bed pickup with a fiberglass bed cover. I had a six inch thick foam pad in the bed for emergency camping. With the cold weather sleeping bag I would have been fine for just part of a day.
My husband has a 45 mile commute each way 3x/week. He keeps a complete winter survival Get Home Bag in the car. In summer, he switches it out for one prepared for hot & flooding weather.
You just need to think ahead. Our plows have been known to not go out for 24 hours if it is really bad in winter and right now, the Planning Commissions are dealing with earthen dams that may not survive another few years. FEMA is making plans to buy out homes in some low-lying areas. We have some road areas that routinely flood every Spring and Summer.