My dad found a bunch of old notes (do you call them bills?) in his room, which are from the Birds series. They are all $20 or smaller. Most have writing and lots of folds / creases so are of no numismatic interest over here.

Can I still spend these on my next trip to Canada which will potentially be this summer, but might not be until next summer, when all of your money will be plastic? If not, how can I as a visitor get them changed to polymer notes in Toronto? (Will be coming for only a few days for family events and I think the hosts will be too busy to bother bringing me to their bank.)

PS. I know I can just give pennies to charity, but will I still be able to use say 10 pennies in one go without pissing people off?