I live in an old house, these things all work really well imo. We have abig curtain over the front door and in bedroom windows. Close the doors to rooms we aren't using. Electric blankets. Long johns. We also have a fan to move heat from the wood burner to the front of the house.
People got use to cheap heat, but these are the things people always did before that was available.
My top tip - if you are cold in the night and have to pee, don't hold off. Go, you will be warmer after.