I'm really bothered by the promotional bias in favor of Ngannou and I'd really like to see that hype train get derailed. Stipe has left a cemetary of monsters in his wake to get where he is, and the UFC doesn't seem to have even attempted to promote him favorably. He's fucking good.
As far as who will win, I think it's a toss-up. I think Stipe is definitely capable of stopping anyone on the feet, but not only does Ngannou have absurd power, he also has exceptional timing. I'd say that if it stays on the feet, the odds lean a little in Ngannou's favor. If it goes to the ground with more than 90 seconds in the round, I doubt Ngannou will survive.