We carried survival gear in the winter at all times and especially if we were travelling any distance. We had food, bottled water, blankets, flairs and extra clothes. Also, we had a first aid kit and some other stuff which I have forgotten. I know we had shovels (to keep the snow off the car).
Stacking the odds in your favor. Smart.
I keep my GPS unit in the car along with the quads. It kept me from getting lost in the Southern Tier of NY (near the NY/Penn border. It's easy to use and economical.Nothing is cheaper and easier than flares and "waterproof matches" are a must. A mirror is an helper. And yes, you can start a fire with it.
I have a buddy who got lost even though he had marked his trail. He said: "Don't tell" but "I got down on my knees and prayed". He now travels with a cell phone and a GPS unit and checks in "someplace" before he travels into the unknown.
My dad always taught me to keep extra blankets, hat & gloves in the car in winter.
My Dad lived in very cold climates. He told us being stranded on a road in a car with snow and cold is a life threatening emergency and should be anticipated with a family plan of action...just like if there was a fire in the house. My Dad's first rule was that you have a better chance to survive (most times) by remaining with the car. You play the odds and take your best shot. Sadly,the Dad would be alive today had he done this.