That's too soon, imo. We still got more backstory to be revealed about the history of the shinobi world. I'm going to say this war will end around the 700th chapter mark. We know there will be a Naruto vs. Sasuke fight, as foreshadowed plenty of times before. I'm guessing that fight will last for 10 chapters including the build-up to it. And we have to see the aftermath of that fight... will anyone end up in the Hokage's seat? What will happen to the shinobi system as a result of this fight? I'd say Naruto will end around the 730th-750th chapter mark.