It could still ferment out, though you did toss a small amount of yeast into a huge amount of beer. As long as the yeast does not become to exhausted and can keep eating, breeding and pooing alcohol you should be okay... But it could be stuck. So you can take this advice with a grain of salt as I only have limited experience with stuck fermentation;
If I were in your shoes, I would take a reading every 24-48 hours and so long as it continues to drop keep the statues quo and leave it alone. If it was not moving within 3 days I would probably try to raise the temperature slightly (like 2-3C, your in Edmonton which is probably just as cold as Calgary now) and see if that helps coax the yeast back to life. If within 7 days its obviously stuck that is when I would toss dry yeast in.