By opposite wall, do you mean the adjacent wall, or the wall completely across the room? And I dont understand your question of "extend" versus "reroute". The pipes need to get to the new location. That can be done in the wall, or if there is a basement, it could be done there.
The only "big" question is the vent for the drain. Depending on what code you are under, the vent will need to be within about 60" of the trap. If your new location puts the trap more than 5' from it's present location, then the vent will also have to be relocated.