Also, if you know that you're in for a bad winter or bad season of any weather, stock up on supplies at the start of the season. Use them up but replace them as you go. That way, you are not going to be stuck out of food when there's a storm warning and everyone runs to buy all the milk and bread from the grocery. If you absolutely MUST have milk but you're worried about it spoiling, get powdered milk and bottled water. It's not the same as fresh milk, but it's real milk and you can drink it and use it for cooking (which is why it's nice to have a camp stove for emergencies)
Speaking of powdered milk, I actually cook with powdered buttermilk more than I use fresh because it gives a better texture. If I want a strong buttermilk flavor I will use regular buttermilk and add a few spoons of powdered. That way you get a real taste of buttermilk (like in buttermilk biscuits).