It is true that Australians and Canadians find themselves to have certain things in common, both being former dominions of the British Empire – but that doesn't mean that Canadian provinces have particularly strong salience for Australians.
Australians consume a lot more American media than Canadian media; and the US is a significantly more popular travel destination. I have a much better idea of the difference between New York and Florida than the difference between British Columbia and Ontario – I've been to both New York and Florida, as I said I still haven't got around to visiting Canada; even before I'd ever been to either, I'd watched countless TV shows and movies set in both, and that gave me a certain image of both in my head (and actually experiencing them in person wasn't hugely different from my pre-existing mental image). I think of Canadian provinces, and my mental images are a lot vaguer. I think that's generally true – the average Australian, if their idea of US geography is somewhat patchy, their idea of Canadian geography is likely to be a lot patchier.