All true, but none of this changes the fact that it's considerably more energy intensive to operate in a colder climate.
And as I explained, that really doesn't matter if it's so hot you can't expend any energy. You end up doing nothing either way.
I had the misfortune of renting an apartment with electric heat. My biggest bill was $250 for a month. The same apartment in the summer, keeping it cool with a window shaker never topped $100. What's scary is I never kept the apartment above 67F in the winter and shut off the heat when I was out.
Despite the cooler denser winter air fuel economy suffers in the winter as well. The slight increase in combustion efficiency is offset by the spinning tires and prolonged warm up periods (not for the car, for the person)
As I mentioned before food can't be grown once the temperature drops below 0 and food needs to be trucked in from further distances. This adds to the bottom line. And the bottom line is cold makes things a lot harder to deal with than heat.