After reading the book "The Death of WCW" I tend to agree with the authors, the problem was not that the wrestlers were "old" per se, the problem was they were not mixing things up enough. You had e same main events every week, the same rivalries, and they were not pushing new talent at all. So my "WCW survives" would look as follows (with a POD being 4/20/98 when Hogan beats Savage for the WCW title with Bret Hart's assistance in OTL).
Hart still attacks Nash but then walks out of the ring after attacking both Hogan and Savage.
Following week he calls NWO and NWO Wolfpack both "an embarrassment to the sport" and goes on a long tirade about "what wrestling should be like" and calling himself a throwback to his fathers era, when people didn't just "flash their ass on TV and embarrass the sport" (now we get an angle for Hart, something he hasn't had since he went on his "pro Canada" heel kick in WWF two years earlier. We also get where he is going with this, he sees the NWO as the D-Generation X of the WCW and wants a return to a simpler time when heels were Iranian and the good guys drank milk).
Later in that episode he is seen watching from the sidelines with Jim the Anvil and Bulldog (not teaming the three up from the start was stupid IMO).
After a typical embarrassing performance by Raven's flock (let's have a Scotty Riggs-Disco Inferno match end in a Disco victory) The "Old School" comes out and curb stomps Raen's flock before recruiting Kidman.
Similar recruitment with Wrath (Brian Clark) and Brian Adams, who form a tag team that feuds with Nash and Hall. Syxx feuds with Kidman.
Old School claims to has both NWO factions but really seem to focus only on the Wolfpack. At a PPV Hart versus Lugar we discover why: Hogan comes out in the Red and Gold as a member of the Old School.
That angle gets maybe 6 months to a year of play before Hogan is jealous of Hart as champ. He starts feuding with Hart, ditching the red and gold for the black and white...but as a face. Says his era is over and so is Hart's and it is time to step aside for the young guys. And says Hart is "living in the past" or something like hat. Have Goldberg, Perry Saturn, Buff Bagwell, Cris Jericho in his corner, and have him promise to retire after the match so that the WCW can hold a fair tournament to determine the next champ.
PPV: Hogan pins Hart, and keeps his word and steps down.
Next PPV: tournament to determine next champion. Hogan on the sidelines backing WCW wrestlers. Goldberg emerges on top.
Goldberg feuds with Hart, Nash, few others, Hogan not seen, giving wrestling fans a break from Hogan to allow the sport to recharge its batteries. Hogan is told that he won't wrestle for the next few months but will be here and there on Nitro.
Now if (big if) we want Hogan back we can have Goldberg do a heel turn or have him lose to some other heel who calls out Hogan. But if the sport looks like it is doing just fine without Hogan, we can push him out or even release him from his contract. The thing we get here is:
Some fresh blood into the stale NWO storyline and a gradual phasing out of NWO as a new force in wrestling emerges.
A legitimate PPV and a legitimate story selling Bret Hart in a WCW title run
The biggest possible Hart-Hogan match possible under the situation (Hart is champ, Hogan is challenger, which gives it a special irony. Also Hogan's retirement will give the match more weight.)
Then we get a legitimate tournament to crown a new champion. If all goes well fans will tune in and the WCW survives it dark days.