If stoic Zoro isn't handling it well, I'm not sure I want to see Sanji's POV of this...might end up a compilation of all the swear words he's ever used...XD

Its Luffy and his indomitable will to live...I'd say midfifties maaaaybe even 60 if he stops with all the near death experiences...^^; though even if he lives to just 50 his reign would have been a lot longer than Roger's I'm guessing since Gol probably set out in his 20's (and who knows how long it took him to become King...Luffy's likely to do it in a year)