I use an electric blanket at night, and on really cold nights a space heatier in my bedroom set at 20. During the day in winter, it's 20. Summer I have no AC except my bedroom.
If it's cold, just wear some extra cltohes and save money. In Japan, we don't even heat our houses at all in the winter. We just wear more clothes and electric blankets are common. We also use a "kotatsu" which is a small table that is heated under it, and a blanket tha goes over the frame and under the table top. However, this is probably not common anymore, since we have adaped western lifestyles.