In the comics, I believe that once the Governor is defeated (killed) Rick and Michonne wind up leading the survivors at Woodberry. However, we need to keep in mind that the TV series differs greatly from the comic.

Here's a twist to consider: "Neegan" is a character in the comics that protects survivors for a price (whatever he wants, mainly food and such; what if Rick and the crew wind up fleeing the prison, then meet up with Neegan who in turns helps them take back the prison... and then he becomes the main bad guy. It's a thought.

As it stands now, I do not know how Rick's group can win unless they resort to gorilla warfare and surprise attacks at night, used to thin out the fighters at Woodberry. They must go on the offensive if they want to win OR Andrea must kill the governor. At this point, I would be willing to bet that the governor kills her first. Who knows? It's fun speculating, though.