Even with summer courses (and without coop), there isn't enough room (especially with the limited selection of summer courses that are offered). I have only 2 electives in years 2-3.
You can take courses while on a coop term, but you have to get special permission to do so. It's a ton of extra work, not really sure a minor is worth it lol. With all the extra credits I'd have (beyond the 120 needed for my HBSc), I might as well just get another degree