I agree: the only place for this to go is from survival horror to RTS.
As long as they have new issues to face, they can always keep it going under the live-action kind of approach. I'm probably missing stuff, but a brief timeline:
1. Rick wakes up & has to survive (thanks Morgan), then finds his family
2. CDC (ka-boom!)
3. Hershel's farm (RIP Shane)
4. The prison & the Governor
5. Termites (Bob-b-que!)
6. Hospital (bye bye Beth)
7. Alexandria (misc. issues)
8. Wolves & quarry zombies (RIP)
9. Gregory's group & Negan's Saviors
For starters, I really hope it's not another get-kicked-out-and-move-on bit. Kicked out of the CDC, then the farm, then the prison, then Terminus, then the hospital (sorta), so...c'mon. Negan's group can prove to be fun because they travel in units rather than as a whole, so they can optionally attack them in groups rather than as a single, giant force. Plus there's trading & settlement opportunities with other "good" groups, which is kind of like the colonies from early America, which can help to rebuild civilization.
One of the things that frustrates me is how quickly they put things to bed & move on. Like Terminus was a huge huge huge goal for them, they get captured at the end of the season, then at the start of the next, Carol pops 'em out and they pretty quickly finish them off at the church. I was hoping for at least half a season of craziness with those guys...not as stretched-out as the Governor's story, but at least kinda meaty, you know? Same issue with the Wolves...all this buildup with the "W", the guys that Morgan runs into, even the comic that the girl was reading...all for pretty much nothing. I was hoping there was going to be an awesome bossfight or something, but it was just kind of a quick siege during the zombie run through town, and then Rick & Carol finished the last of them off. Pretty anti-climatic.