FWIW, the (original) battery on my 2004 Jeep Liberty died last week. (No, I didn't pull a baby brain move. It was about 10 years old so probably overdue to be changed.)

It wasn't a survival situation by any stretch of the imagination. I was in a retail parking lot so had easy access to shelter, but I decided to wait it out, as sort of an experiment. I was shopping for maybe 10 mins before I tried to head home, so the Jeep had time to cool down before I got back in it. After that I wasn't stuck for more than maybe 45 mins before my hubby came and rescued me, but it was a very windy sub-zero day and it got cold in there fast. I was really glad that I dressed for the weather (insulated boots, Merino wool socks, LS thermal top, fleece jacket, thinsulate hat And gloves), and also for the extra down jacket and mitts I keep in there. (To be fair, I do have my own personal internal heater right now, so wasn't wearing thermal long johns as I would be any other winter.)

Expanding on Russ's post above, my Jeep now has a brand new sub-zero battery as well as a brand new alternator.