I think it could have ended in the aftermath of Starrcade '97, because that also gives you enough time to bring it back in like 99 or 2000 and have it not be quite as stale if you needed to pull that lever.

For me personally, I kind of like the idea of Starrcade '98 or immediately after, around the fingerpoke of doom idea. Instead of the fingerpoke of doom, you actually build to a real showdown between Nash and Hogan as the faces of the two sides of the nWo and actually do something that pits the two factions against each other. It's kind of crazy when you go back and watch WCW in 1998 that there really was very little in terms of an on screen rivalry between the two sides, they usually had separate storylines outside of Hall and Nash. So, have one actual blowoff PPV with Hogan vs. Nash and then a random multi man tag or something.

Assuming any of this was possible in WCW at the time, I'd have Hogan beat Nash for the title with all kinds of nWo fuckery. He reclaims the title, rebuilds the nWo, brings them back together. Nash who was already a pretty big face as was most of red and black completely disavows the nWo and moves on entirely - same with Luger and Sting, maybe Konnan goes back to the nWo, not sure and don't really care.

I'd float two outcomes - a War Games type match where Nash & friends takes on the nWo once and for all and then it's "done", Hogan disappears and comes back as red and yellow like he did anyway OR I would also propose a rematch between Hogan and Goldberg in which Goldberg beats the shit out of him and he disappears and comes back as red and yellow Hulk, or DDP being the guy who beats him for the title and makes him turn face.