Exactly! A standard euro engine translates to a premium fueled engine in NA. No need to recalibrate etc. The emissions are close enough now that perhaps just a slightly large cat converter would be enough.
For higher elevation areas like Calgary (1200m above sea level) i think you can get away with using lesser octain fuel because the air is only about 86% as dense as at sea level thus, lesser chance of knocks.
I know, i know.. you say, "OMG, you bought a f-ing BMW, just use the premium, how much do you really save buying regular fuel!"
you are absolutely right, and it pains me every time i see VW/Audi turbo cars being fed regulars at pumps, but really.. i don't think it will harm the engine at our elevation.