The coin exchange is at the Mariott Downtown at 525 Bay Street in the Adelaide room (10-6). It also continues Saturday (10-6) and Sunday (10-4). They have a pop-up shop with other coins you can see in person (like a mini-mint store), and a large cardboard cut out of the loonie. There were no lines when I went. If you're in the area, it might be worth popping in.