The next episode is the last of the season.
I'm almost certain that the end of the season means the end of these characters and story, and the next season will have new characters/new story (same theme obviously).
My guess is Lee will live until 3/4th of the way through, Clem has to kill him, and then you control Clem for the last part of the game alone and eventually run into her parents and a nice little group of people.
That would be my "best case scenario".
"You lack the requisite spine and testicular fortitude to study under me"