[jly]

> a -40C day is usually much more enjoyable than a +40C day

I can't believe I just read this :)

With an appropriately-sized and designed HVAC system, home, and fans, 40C is completely comfortable indoors. If your home is designed well, you probably don't even need a whole lot of energy to achieve this.

The difference is, in 40C you can also be outside at any part of the day, for any duration (especially in the shade). I haven't spent a great deal of time at -40C, but I can tell you my experience is that it was pretty miserable to be outside in, even bundled up.