Spent most of my life in Southern California were we do pay attention to insulation and weatherstripping. But I was out of the area for six years while on active duty.
First I was on the Gulf Coast of MS for tech school (Keesler AFB in Biloxi). I brought my wife out and we arrived at our apartment on New Year's Eve 1976. It was raining a bit. Next morning, 1977, I looked out and our car had icicles on the bumper. The apartment had no weatherstripping and apparently no insulation and was miserably cold.
That was the year the US had a very bad winter. Our instructor called the break early when he heard that it was snowing. Yep, it was snowing on the Gulf Coast. Last about 20 minutes, but we got snow drifts upwards of a quarter inch tall. Locals had no idea how to drive in that stuff (kind of like Southern Californians when it rains). But what made the headlines was that while almost all of the lower 48 states (AKA CONUS) were suffering below-freezing temperatures, it was 45°F in Alaska.
From that I was stationed for five years in North Dakota. It was interesting to see how everything was adapted for the cold weather. The houses were almost perfect cubes in order to maximize internal volume while minimizing surface area, thus preserving heat. Every business and most houses had two sets of doors to the outside, kind of like a spacecraft airlock except this was to keep heat from escaping and cold air from blowing in. One night there we watched "The Thing" (1951) on TV (the original with James Arness playing the Carrot Man -- I think he was the reason why they filmed the outdoor location shots just west of Fargo). We laughed at how ridiculous the early scenes were where the aircrew goes into the base CO's office and every time the office door opens snow and the cold wind blow in and sends the papers on his desk flying; nobody would ever build an office like that which we knew by having lived it.