This is a simple suggestion:
When it gets down to one vampire and one town member, that town member should win along with the vampires.
When I was just in this scenario, I was transporter. It should have been at worst a draw (when did that stop being a thing?), but I immediately lost.
Since vampires can't actually kill townies, there is only one end to that game, which is for the townie to be converted. Saving the day it takes to arrive at that end seems wise, but making the townie lose that victory not so much.