You can find crème fraîche in the dairy section of most large grocery stores in Gatineau (Loblaws, Metro, IGA). I'm not sure if that is also the case in Ottawa. Some things are easier to find on the Gatineau side...
This may be heresy, but when I'm in a hurry, without buttermilk and can't wait 24 hours, I just whisk together equal parts of whipping cream and good quality sour cream and let it sit on the counter for a couple of hours. Sometimes I sweeten it with a bit of sugar or flavour it with rum for desserts.
Tried some from the Market a few years ago; bought some at Ottawa Bagel, Wellington Street - EXCELLENT. Tried some from Nicastro's, Wellington. Back to OttBag: other 2 were like thin sour cream; OttBag's was thick, creamy, not especially sour, ingredients were cream, bacterial culture (like Two Fat Ladies used to say: all you need are bugs and cows).
I suspect the product on the shelf at OttBag was farm-direct even if probably pasteurized and not (re-)created later from cream, buttermilk/yoghurt and 24 hours to brew.
Pasta lover