It's kind of late, but here's what I thought about the only way to see Zkk happening.
I never had any doubts that Luffy would beat Kaido in 1x1, after all he is the protagonist and he has always been like that.
But after Luffy defeats Kaido, I believe it will be similar to the fight with Rob Lucci where he will be incapacitated and unable to move and Kaido will be unconscious on the ground. This is the moment when I believe the Nine Red Sheaths will discuss Kaido's death, as they tried to do in Chapter 993. But this time, Zoro will be along, who will simply ignore the conversation, take the lead and kill Kaido.