Are you able to move yourself through the airport? Or will you be relying on an airport chair? I'm also a wheelchair user (para) and I would say this is enough time to make the connection because you get to skip to the front of the line at customs. Make sure the other people in your party know to wait for you (you'll be last off the plane) so you can all go though the crew/ diplomat line together.

I don't know too much about using an airport wheelchair or how fast the staff are with pushing, but the service in Canadian airports is pretty excellent.

It's a bit tight, but with no delays you should be fine. With delays....you might not make it. I make one hour connections to the USA pretty often and while they can be a bit stressful, I haven't missed one yet!