That's actually not true. It would be a multi quadrillion dollar venture to insulate every house in the US better. There are millions of homes, and a lot of them have poor insulation, and it's not something you can just bolt on, you have to move out all the furniture, pay for somewhere for the family to live, tear down all the walls, add the insulation, re-drywall (Or other wall) everything, paint everything as it was, move back the furniture and family, as well as pay the family a considerable amount for taking their home from them.
And that's just the US. Our houses are fairly cheap which is a good and bad thing. Cheap house = less cost = less quality. They will stand for centuries, but they won't be well doing it.
I guess you can't compare the climate in the USA with Australia. I think fairly decent insulation has been pretty standard (if not, even required) in Australian homes for how many decades? Does anyone know?
Heck yea I can. We may even have it worse. We can do anywhere from -20 to 100F where I live in Schenectady, NY. More southern New Britain states like Connecticut can go around 10 degrees higher, but can still be that cold in the winter (Google has F to C conversions for you)
Now we RARELY get 50c (122F) weather here, but it's not much of a difference, it's unbearably hot here. One difference is that we can get TERRIBLE humidity. It can go up to the 90% range, with 100% being raining (Some days it feels like you could start swimming in the air it's so thick) I am of course referring to Schenectady and most of New York, don't bang down my door complaining you get different results elsewhere. I mean today on a very dry, very cold day, we have 65% humidity 1:18AM.
So no, we may even have it worse than NSW, if not, then we don't have it much far off.
Did I mention we got probably around 6 inches (Around 16-18cm) of snow today? Not fun to shovel it...