The opportunity is if Ryan continues to obstruct Trump's election campaign and Trump wins anyway. Especially if he wins big, which I believe he will if he carries Pennsylvania and Ohio. At that point, Trump will have a LOT of leverage over Congress and the party, and if he says that he needs a speaker who he can work with, who believes in his agenda, and asks the Republicans in the House to give him one, and throws his support behind a congressman who is up for the fight, then he might just be able to get his own guy in. I think most Republican Congressmen are on our side, but they are told that they have to play ball when they get there and so they do to advance their power. Those who reach power, committee chairs and such, are pretty much in the establishment's pocket. But there are a lot who we can still reach.
If that happened, I could see Ryan trying to use Democrat votes to retain the speakership. Could get interesting.