Actually running is the worst thing you could do vs GGG. Its easy and common to say "run from the puncher". In reality GGG style is the absolute worst matchup for a slickster or runner. You cant run from someone who cuts the ring like GGG, and has shifting skills like GGG. You just end up like Jacobs staring at Pirogs incoming fist with deer-in-headlight eyes wondering how the how he was still on top of him and wondering when he is going to wake up. Canelo has a style that can hypothetically be competitive, another example of a competitive style matchup is Tureano Johnson - if someone could actually stay on his chest. (not that I think Johnson could, levels, but a bullrush and brawl approach could be effective)
This is why I'm giving Rubio an outside chance to pull it off. I actually think Canelo will go into retreat the moment he taste GGG's power. But he'll attempt to stand his ground initially.
ggg would knock canelo out by round 2 remember canelo is not fighting a welter or a jmw he is fighting a 160 with power of a heavyweight