It might be days before the power comes back on.
For many of us, the quick solution is to turn to wood. Heating with wood is historically the most common means of keeping your home warm. Throughout the centuries, people used wood to warm everything from tents to palaces. It has withstood the test of time quite effectively, providing warmth for millions of people. That makes it a survivalist's number one choice for a back up way to heat your home.
But it takes a lot of wood to keep your home warm. In a long-term crisis situation, you might run out of wood before the power comes back on. Or, perhaps your wood-burning stove is unusable.