It's mostly true, though I'm not sure about your example. The French word for potion is "potion", and I've never heard it used with a meaning other than "elixir".
A better example would be "embarquer/débarquer". In France, those words, meaning "entering/leaving a boat" ("barque" is a slightly antiquated word for "boat"), have fallen into disuse as boats became less and less a common feature of life. However, in Québec, these words are still very widely used, but we apply them to entering and getting out of cars and other vehicles. Now, for that, a Frenchman would use the more general "monter/descendre (de voiture)".
That said, if you consider accents and phonetics rather than actual vocabulary, it would appear that we
are much closer to 17th century French in Québec than in France. You see, in Québec, we only live side-to-side with each other and the English. (And Native Americans, of course, but that's unfortunately very minor.) Whereas the French are surrounded by a variety of strong language populations in their own rights and their speech has evolved in reaction to this environment. I've heard Parisians say that Québec French is actually
purer by comparison, for that reason.
Ironically, we in Québec are often shocked at how much the French are borrowing from the English. They say "shopping" where we would say "magasinage", "parking" where we would say "stationnement", "e-mail" where we would say "courriel", and so on. It's really quite strange. Maybe we've grown more defensive and protective of our linguistic heritage. We can't take it for granted, or we risk losing it.
Still, France French and Québec French are best described at twin brothers, separated at 10 years old and growing up in different families afterwards. There are definitely differences, but it takes only minimal effort for a Québécois (or any other Francophone, really) to adjust his speech and be understood in
any French-speaking country in the world.
EDIT:
You mean the fact that compared to an educated Parisian, most Quebecois sound like country bumpkins and salty sailors?
Parisians think
anyone from outside Paris sound like country bumpkins and salty sailors. That includes every other region of France. (Marseillais have a great accent, by the way. Very expressive and somewhat fun to hear.)
You know the difference between God and a Parisian? God doesn't think he's a Parisian.
