It was a fantastic thing mom and dad had a king-sized bed.
Nowadays, nearly everyone has a whole lake apartment HVAC method and zone control.
When I was growing up in the 50s and 60s, all of us didn’t have heating in our upstairs.
We counted on one main register that sat in the middle of the hallway to pull enough heat from downstairs to moderate our study rooms. I remember times when our dad would block off the register, mom would put curtains up to the stairwell, and all of us would all sleep in the family room to stay moderate and cozy. It was a camping in the middle of your family room type of night. I remember one certain night, when it was nearly 20° below zero outside, and our windows were covered with ice, and all of us couldn’t sleep because all of us were shivering so badly. We didn’t guess the gas furnace had quit working, but dad did. One by one, the four of us youngsters crept over to mom and dad’s room and quietly curled up next to mom. It wasn’t until our older sister came over and hopped in bed that all of us realized daddy wasn’t there. Mom told us to curl up underneath the covers and try to get some sleep while she threw on her robe and headed downstairs. Several minutes later, I heard mom and dad talking as they were coming up the steps. Dad was talking about how they had to get a up-to-date gas furnace because he didn’t want to need to go without heat again. Mom agreed about the gas furnace, and she laughed and asked what they were going to do about sleeping tonight? Dad said they didn’t need a gas furnace tonight, as they both crawled into the one side of the bed where all of us had not spread out.