The only thing saving Trump from criminal prosecution for any number of crimes he's committed while in office is executive immunity. The only thing potentially saving Trump from being impeached by the House is --- well, nothing. I bet he's fucked there (again). The only thing saving him from being removed from office after his trial by the Senate (or the Senate voting after Biden starts his term to complete the impeachment process with 2/3 vote) is the craven nature of the worthless Republicans in office. As of now, there is nothing saving Trump from crimes committed while not in office, assuming no statute of limitations issues.
Edit: The lying moron has been impeached again by the House.
Edit 2: If I had to guess whether he would be convicted on a charge of incitement based on the evil that a) always spews forth from his anus of a mouth or, b) the evil that spewed forth from his mouth on January 6th, I would guess that he would be acquitted. Still, that has nothing to do with whether he could or should be impeached.