There is one held each year in May in Sherbrooke, QC. that I have been attending for a few years. The only downside is that most of the demos are in French, however just about everyone speaks English, and will talk to you in English. It is a 2 day event with many major rod companies participating. It is heavily attended by folks from the Gaspe region of Quebec.
It cost $10 per day which includes a nice lunch. One of the local motels gives a discount for attendees, and many of the demonstrators, and sponsors stay there. Google Sherbrooke Spey Clave for more info.
You can catch a lot of fish, and you can keep a lot of fish. But you can't do both very long. Jim Timmins