Depends: in this scenario, survived how? They were beaten but still survived because the volcano shot them far away? Or It Is a completely different scenario from the Wano we have seen?
Anyway, I think Kaido, having finally found Joy Boy and the fight of his life, would lay low. At best, he would become some kind of, idk, Kuzan 2.0. but in a cheerful way.
His crew would still have been destroyed so he would be on his own.
In the end, maybe, he could join BB if he still wants to fight someone. Idk if he would Aid Luffy, but it's possible.
BM would probably return to WC first and then she'll probably go against Luffy since Wano's absurd writing prevented her to do what he wanted to do at all costs.
Also, she would still have her crew and Empire, contrary to Kaido.