It'll definitely end with Luffy and Kaido as the last two standing to bring the fight to it's conclusion, but Kaido will be injured prior to it. The way it seems to be being built up is that the perception of Kaido needs to be shattered, while at the same time Luffy needs to be announced to the World that he is here, and a real contender for the throne. There is no other time to do this other than Wano, because after this we are moving towards EoS.
We've seen that even those on the level of the scabbards can put up somewhat of a resistance against Kaido if they work together, but ultimately, they lost in the end. The only person Oda has prepped to go the full distance in this fight is Luffy, and it happened over the course of two and a half arcs.
Are we to believe that Law, who needed Luffy to defeat Doflamingo in his steed, is suppose to magically be on Luffy's level, after all that Luffy has been through, while Law has gone through no type of transformation, or given any significant power ups? What about Zoro and Killer who just took each other out a couple dozen chapters ago? Luffy went through all that just to catch up to them? Kid is the only ambiguous one here, because the only people we know he's lost to is Shanks crew, and Kaido, but even then, how far strong does Oda plan on making him?
People need to take their beer goggles off and realize that Luffy has been the one Oda has been prepping for this fight extensively. The others are there and will contribute to it, but the one who will ultimately be standing in the end to finish off Kaido, is Luffy.