About five years of solid booking and storyline development. That seems to be the case outside of rare instances for downbeaten wrestling promotions to get back on their feet.
Even then, though... Just seems like now more than ever, they need to try to find some way to stand out. And "TNA trying to stand out" usually doesn't end well.
Weird to be the one burying TNA in a thread, but imo, much of what's hurt TNA recently has been how much the other promotions have gotten stronger here in the states. Lucha Underground was the talk of wrestling fans for most of the year. ROH had a lot of upward momentum and New Japan's kept rolling on, as NXT's had as steady as years get. It seems like, as they would try to repair and resuscitate their image, they'd be left with plenty of catching up to do as they compete in the "indies".
A lot could change in five years, but if TNA establishes itself as a place to run to find logical booking in 2016, that's already what we watch NXT for. Right now they're delivering exciting in-ring action, but ROH/NJPW have such long reputations of being the go-to companies for quality wrestling on top of WWE arguably having their best roster ever of ring generals, it only goes so far. It's not a place to go for star power, they've never truly booked that way despite Dixie's love of bringing in big names, and if they want to try to create a way to truly innovate the business, get in line behind Lucha Underground.