Winner will unify with Saunders / Khurtsidze winner hopefully. I say winner because I don't think it's absolutely clear GGG wins. 50/50 fight for me. Canelo points or GGG late No! Edit: KO not No
The biggest money fight available will be a rematch if it's close. If that's not possible the best money is for Saunders or Eubanks. Perhaps he gives Jacobs a rematch which will sell pretty well. I'm not seeing a big money fight at 168 that pays better than the brits. Eventually he loses to Andrade in 2020 to round out his career. By that time Andrade will be better and ggg will be too slow and old. He will have had several huge money fights, 1 or 2 losses and a hof career. And the posters here will continue to debate his legacy.
I don't think he'll be fighting in 12 months time. Canelo, and unify if he wants then retire. I'd say hes very level headed
I would advise you not to count your chickens before they hatch. I'll be rooting for GGG but it's by no means certain that he will KO Canelo or even win. Anyway, if he does win, I expect he'll try to unify the WBO title, then rematch Canelo.