There would be a big difference. The US has a market 10 times Canada's population. As a result, it's more than worth whatever bureaucratic hassles a company must go through to access such a huge labour and consumer market. With pan-Canada having 1/10 that market, and itself being split with separate parts having their own monetary policies, and possibly citizenship policies too, suddenly smaller multinationals might start to think it not worth the hassle for such a small market.
In short, owing to the population, you can't compare Canada with, let's say, the US, China, India, Russia, the EU (though multiple countries, most do share a common currency and free labour movement and free trade within the Union, not to mention the UK itself is 5 times Canada's population), etc. Population-wise, we're light weights.