I sorta would be.
There's not much further they can really take the premise. It started to wear thin by the end of season 2/early season 3. It only maintained quality by shoving in a good antagonist and some whacky road runner-esque hijinks through season 4. They're already playing around with murder and potential child killing. Where exactly does one escalate from there?
They took away aforementioned great antagonist and the other major one is likely to be "put on a bus". The cartels have been thoroughly dealt with, so it's fairly unlikely we'll see much outta them unless they try to whip out Gus' family as one final antagonistic force..
Between all that, I don't really see where they can take this. About the only major thing left as I see it is for Jesse to realize how much of a monster Walt has become and subsequently kill/stop the monster he helped create several seasons ago. With possible subplots involving the family finding out more about the scope of what he's really been up to. Since he effectively confessed to multiple homicide with that little "I won" remark. . But that's just me.