I'm not sure what you're due from Air Canada, but if you have travel insurance you should receive trip delay funds or have trip cancellation coverage. I know my package pays out around C$35 per hour of delay up to 12 hours and C$15 per hour after that, so for 20 hours= $540.

I'll add that I'm really shocked that AC hasn't rerouted you the passengers on flights via YVR, YYC or YYZ...