Thanks jzmtl and Alan_ for your replies.

I was able to confirm that my Nokias can still call 911. They are going in the glovebox of each car with a charger and an information card. (And one is going into my parents' car, whether they like it or not. Their offspring can be stubborn too.)

From the website of the official Canadian telecommunications regulator (CRTC):
"What if I have a cellphone but do not subscribe to any service?

Even if you do not have any pre-paid minutes or a service plan, you will still be able to dial 911 in an emergency situation. However, you will receive wireless 911 services as they exist today. Emergency responders will not be able to use the enhanced features to determine your location with a greater degree of accuracy."