To my knowledge, no Quebec microbreweries own an Ontario-based production facility. The advantages are so great that some of us are seriously considering it, including me and my own company. We're based in Gatineau, across the river, and it would be relatively simple for us to establish a production facility in Ottawa or in the Ottawa Valley. We could therefore take advantage of the same interprovincial agreement that the large brewers have taken advantage of in the past.
But for most Quebec microbreweries, it doesn't make economic sense to do it unless they really want to dedicate themselves to the Ontario market.