They'll have a lot of choices. Order of operation and timing. Line of succession doesn't run through people, it runs through offices.
But if Trump is out? November becomes a rout.
Replacing a vice president is how we got Gerald Ford as president following Nixon.
That's why I mean the further line of succession is for disasters and attacks.
It's a low-percentage scenario, as it requires two unlikely events together.
That's not impossible, but not likely.