I don’t know about Mitch, but Ryan is completely secure as his congressional district loves him. As Speaker? You need to ask every Republican in the House save one who voted him into that job.
What’s the point in engaging in these fantasies that you know have zero probability of happening? Just like to hear people say “Yeah, he’s gotta go!”?
Let me answer you this way. If a good sports team is not winning...who goes, not the players most of the time, the coach or coaches go out the door!!! You pay a leader to lead and win...not lose!!! End of story!!!