Here's one thing he might possibly do (I doubt it, but as long as we are speculating, here goes) is to win his home state, denying an electoral college victory to the two parties and throwing the election back to the House, which is not compelled to even vote for one of the nominees of any party.
NBC released a poll today in which Hillary has a one point lead over Trump when Johnson and Stein are included as options. I think things will get very interesting before this election is over.
