I have been outside with my son a lot. A) snow is fun and B) You don't need to heat the house all day if you're not in it! He is bundled up in so many layers.
This is where the warm homes discount really helps. I try to budget each year without taking it into account and then "use" it up in cold snaps like this. It really helps to have that buffer. That and lots of hot drinks, blankets and a hot water bottle.