Dave,
Athletics Ontario has a listing on their site about all the sanctioned clubs in the province -
https://athleticsontario.ca/clubs/ That may be a good place to start.
Keep in mind that there is an ebb and flow in the year with Club Level runners of what they are focusing on, and also, from my experience - weekend runs tend to be the time for longer runs or tempo runs, and not for interval type of training.
That being said - training with athletes who are just that much better then you, is never a bad thing. Pushes and pulls you along at a higher performance level.
Years ago when I started in triathlon I came from a high-performance running back ground and I maintained, my involvement with training with real runners throughout my time in triathlon - generally I would do the interval workouts and tempo sessions with a group of good runners and my long runs on my own.
Steve Fleck @stevefleck | Blog