Ontario grocery stores will be allowed to sell up to 46 million six-packs of beer per year in Ontario, according to the Toronto Star. This sounds like a lot of beer but according to the beer trade association, Beer Canada, Ontarians purchased 7.9 million hectolitres of beer in 2014 (790,000,000 litres of beer).
46 million six packs of beer is, at 355mL per bottle (0.35L), 16,330,000 litres of beer (163,300 hectolitres of beer). So of the 8.9 million hectolitres of beer consumed in Ontario, grocery stores will be able to sell a maximum of 163,300 - around 2% of total beer sales.