When winter weather starts to get ugly, it’s times like this that your hour-long commute on the interstate can turn into an unexpected adventure, leaving you stuck in a snowy ditch miles from help. In most cases you can expect to be there for no more than a few hours, says Tony Nester, founder of the Ancient Pathways survival school in Flagstaff, Ariz. and author of the e-book A Vehicle Survival Kit You Can Live With. “Statistically, you’re more likely to encounter small scale episodes where there’s a blizzard, you spin off the road and you’re there for maybe a...