It was 1983. I had a 12 week old infant, and had a terrible time getting the house warm enough. The heat pumps of that era were not very efficient when the temperatures fell below freezing. I also remember my washer outflow hose freezing; I ran a load of wash (see the second sentence :lol
and it overflowed. I ended up sloooowly pouring warm into it to defrost it.
Then, Christmas of 1989 we had snow followed by cold (so it didn't melt immediately) and my neighbor's (out of town) pipes froze. They thought that leaving the thermostat at 60 would be enough to prevent it.