blankets and entertainment. We don't lose power due to cold, ice/snow storms yes, but cold won't break the grid.However Nothing wrong with having an emergency kit and/or bug out bag prepped.

keep the place 55 or so, check for cold spots, like under the kictchen sink, you can leave the cab open so heat gets there. you can also leave the tap open to a drip, if it has a freezing issue, but you don't know if it does yet.

pipes freezing isn't end of world, unless they burst. I've used a hairdryer on a number of them to thaw it out.

only issue i see with your plan is if the fireplace heats up your thermostat to the point it shuts off, and other rooms in your house isolated from fireplace start freezing. depends on how many zones you have, layout of house. go around and check the baseboard heaters if they are warm you good.