Well, Vance can choose Trump. And there is no term limit to the vice presidency.
The Constitution says no one can be elected more than twice and there is no bar to being elected vice president after being POTUS. And if Vance should suffer 'an unfortunate accident' Trump could fulfill the rest of Vance's term as POTUS.
Should Vance gain the presidency due to Trump being removed from office, unless he was also 'barred from federal office' which is not automatic in impeachment/removal proceedings, he could appoint Trump as his VP.
If he 'succeeded' or 'was appointed' to the office, he just couldn't be elected at the end of that term.
Of course either of the above scenarios is highly unlikely.
I hope.