It’s a good idea to pack a bag of supplies to keep in the car when the snow starts to fall. These should include food and water, warm clothing or a blanket, a torch, a first aid kit, a fully charged mobile phone, jump leads, a shovel, an ice scraper or deicing fluid, and some grit, sand or cat litter. This sounds overkill, but while it’s unlikely to save your life, it could save you from a great deal of discomfort.
Plan your route, so that you don’t get lost, and make sure you stick to major roads for as much of it as possible. These are the roads that are likely to have been cleared or gritted, so you stand the best chance of getting to your destination. What’s more, there’s a greater likelihood of encountering a passing car should you find yourself stuck in a ditch.
Make sure your car has a full tank of fuel, so that if you get stuck for any reason you can run the engine to keep warm (though if this happens, you must get out of the car periodically to clear snow from the exhaust; if it gets blocked by falling snow, carbon monoxide can build up within the car with potentially fatal consequences).