[WARNING: This post contains spoilers for The Walking Dead.]
There is no way of knowing when a TV show will run out of road or if they will try to navigate over gravel and broken glass long after that point, refusing to wrap things up before people start forgetting why they loved those shows in the first place.
The Walking Dead isn't necessarily kicking up gravel or nearing its expiration point right now as the cast and crew work on season 5 (which will debut this fall), but producer David Alpert has indicated that producers of the AMC zombie drama do have the far-off future on their mind.
Here's Alpert, answering a question about working with "pre-existing" material during a panel discussion at a Producers Guild event.
"I happen to love working from source material, specifically because we have a pretty good idea of what season 10 is gonna be. We know where season 11 and 12...we have benchmarks and milestones for those seasons if we're lucky enough to get there."
The Walking Dead has diverged a bit from the comic book source material at times, so it's hard to know how vital those "milestones" and "benchmarks" will be and what form they will take. However, if Alpert is referring to the source material that has already been released by Image Comics and Robert Kirkman and not some kind of story bible, then it seems natural to wonder if the Alexandria camp will play a large role in the later seasons of the show and what that could mean for the future of the show.
First, let's establish that this wouldn't be a large leap. We already know that Negan's eventual appearance as a big bad is a "99% lock" and Alexandria has been the port-of-call for Rick and his group since issue #69. At this point, most of the Walking Dead comic book series has occurred within and around that camp.
With that in mind, it would make sense that the show would settle there after Terminus and, quite possibly, a bit of time spent on the road. The trouble is, while there have been some great stories told about the group's adjustment to "regular" life in Alexandria, some significant new characters, the town's institutional naivety and Negan, there have been times where the comic has felt a bit stale because of Kirkman's decision to make Alexandria home base and take the group off the road.
Four seasons in and The Walking Dead has seen four primary settings - the camp/Atlanta, Hershel's Farm, the prison/Woodbury and the Road to Terminus. The Walking Dead has thrived on new scenarios and new challenges as Rick and his group struggle to survive, adapt and also steal back a bit of what they lost from time to time.
Without that constant change, though, it's fair to wonder if the show could stagnate if the writers don't find new ways to amp up the action within and around the walls of Alexandria if/when they get there, because if they don't, then future forecasts could be irrelevant.
The Walking Dead season 5 returns to AMC in the fall of 2014.