This fight depends on whether Calzaghe's punches can sting Canelo enough to slow him down, or if his punches can come quick enough so that it can land right before Canelo has a chance to respond.
Calzaghe's most notable fights were the RJJ and the Bernard Hopkins fights yea?
This fight might play out like the Plant fight since both are much taller fighters than Canelo, but then you can argue that Plant had quicker hands and better mobility than Calzaghe.
Canelo still found a way to deal with it and landed that devastating haymaker that landed Plant on the floor...