I like Cotto and Canelo and if they get it on, good luck to them. But if Geale does beat Cotto (and I think as long as he's not weight drained , it's a very real prospect.), then it's too bad. I don't think it would be a massive upset.
When he got KO'd by GGG he hit Golovkin with some big shots and I don't know if Cotto will take those. Look back at that fight and you'll see just as GGG KO'd Geale, Geale hit GGG with a peach of a shot, but it just had no effect. GGG isn't just a banger, he definitely has a solid chin.