When I lived up north I always had a fireplace. After one particularly nasty ice storm I had to put blankets up covering the doorways out to keep the heat in the one room. Thankfully I had a gas stove and water heater as well so I could still cook and take a hot shower.
Whatever you do, NEVER use a Propane or Charcoal Grill in the house. These give off CO2 and you will die. Same for things like coleman stoves etc. Which are designed for outdoor use.