A few people had already suggested Gentry Lane, Lotus of Oakville or John Scotti Lotus, for this question in the Owners in Canada thread, but I'll post here in case someone else searches for answers in the future.
+1 for Gentry Lane, where I had my pre-purchase inspection last year before sending my car out west. Brian was very helpful, provided great customer service and even found some old brochures to make it feel like I was buying a brand new car. It looks like a long drive from Ottawa, so while you're waiting for service, I recommend hanging out at Annabelle Pasta Bar on Davenport at Christie, which is what I did. Good pasta, and a long Negroni menu.
I didn't get any work done at John Scotti Lotus, but I did order some parts from them last year and can say they were friendly and helpful over the phone, so might be a good option for you too.
There doesn't seem to be a lot of choices in Canada (or North America for that matter) but maybe a local Lotus car club might be able to point you to some other technicians. If you find any, post an update and let us know.