Don't Panic if your home temp drops in the extreme cold.
In our house, it's all about keeping the humidity up. We will cook soups, stews, hot dogs. It's an attempt to infuse more water into our home's atmosphere. Some times, just boiling water for tea or instant coffee will help. Our parents used to put a pan on the register, they knew something!
We also keep our curtains and blinds closed to better insulate our home from our cold windows. If the sun comes out, though, we will open those curtains and blinds, usually to the south, to allow the sun to help heat our home. Windows will radiate heat if the sun is on them.
We also use small rugs and other handmade devices to place at door bases to control the draft. Ann has made some with left over fabric and stuffing. Those help!
We will leave our furnace fan on all the time to keep fresh air in the furnace and keep the furnace temp lower so it works more efficiently. This helps for us, as we have a gravity furnace with multiple thermostats on the unit so it doesn't overheat as it's working to heat our home. We will not lower those stats, as they protect our furnace and home.
My friend Aaron Mollett, a heating and air conditioning expert offered some advice...