Mini Motels
I travel a lot for work, and have on occasion been stuck at a layover over night. Luckily for the most part it was due to mechanical difficulties, which meant the airline had to put me up at a hotel. I recently read that that is becoming rarer as airlines reduce flights and costs. The article I was reading mentioned the Mini Motel, which is intriguing, but probably impractical to lug around on the off chance you might get stuck. (Checking it in, which I almost never do normally, won’t help because most forced overnight layovers leave the checked luggage on the plane.) So unless I can carry it onboard, it isn’t that useful.
Still, might be worth a look as a cheap sleeping bag.