I see it the same way.  McCain, Graham, Collins, and other Republicans will have to have the courage and wisdom to step up and put their loyalty to the principles and welfare of the country before that of their party's president. I think a number of them have demonstrated that they have the integrity to do so.  What other actions and behavior on the part of Trump will have to occur in order for them to take action is anyone's guess. It would have to be something pretty egregious in order for him to be impeached. I'd like to think that he could be persuaded to step aside (given his personality, I don't know if that is possible) before something calamitous happens. How Trump's many loyalist followers would react to this, I do not know.
I may not like some of Pence's politics, but from what I see of him, he seems stable, decent, level headed, dignified, and possessing the temperament to be president. At any rate, I'd probably breath a sigh of relief if he took over.