The whole letting go of his Dark Passenger bit will probably be dropped along with everything else they dropped.
I don't know how I'd want the show to end, but I think that getting caught would be especially bad for the kids. They've been through enough. First, they had a prison dad who is killed, then mom is mudered right in their house, then their stepdad turns out to be a serial killer? That's too much. I think the show could end with him just accepting that being a serial killer is the life for him.