I don't know about modern homes but growing up in the south, heating was an afterthought in many homes. We had an old wood stove on one house and none until we installed a wood stove in another house. Neither had ducts. You either found a spot a reasonable distance from the stove or set a box fan to push air into other rooms.

I remember waking up early to stoke the fire and falling asleep on the floor in front of the stove just to be warm for a bit before walking to school.

I know they cut electricity to a lot of homes in Texas last night and people aren't really equipped to deal with it.