Uncle Ogre,
As always, I appreciate the advice and would like to say, I am working hard on that specific task. While she is not a survivalist, she is quite intelligent and competant. If the presented senerio occured, and I expected the weather to improve by noon the following day, I would most likely hunker down for the over-night and wait for the weather to improve as your chances of survival and getting help are greatly improved at your car if it is near a road-way.
Preparedness is about options and information to make intelligent, informed decisions. It's also about confidence to prevent panic when things start to go wrong. When people panic, they make mistakes and bad situations often get worse and fast.
I have confidence that my fiancee and little one would be ok without me for a day or two, even in the harshest conditions. There is approximately 12 hours of fuel for the generator in the garage, and she would likely wait a while before turning on the generator. During last years Ice Storm we learned that the house temperture dropped from 70 to upper 50s in 1 day and upper 40s in a second day and there is sufficient gear at the house to support that them easily under those conditions.
After the on-hand fuel supply runs out, she would need to get fuel. There is a gas station about a quarter mile from our house, and she is more than capable of getting fuel and refilling the generator.
As I said, it's about having options. About knowing I can get home, even under the worst conditions, if I absolutely need to. That doesn't mean that I will automatically ditch the car and hike 30 miles through blinding snow, but its useful to know you can, should the need arise.