I don't think it can be finished. HxH's peculiar structure and Togashi's storytelling means he can go on endlessly, which I believe it's what's going to happen. We'll get the end of the Succession War, the Dark Continent, Gon's struggle against Gyro, Killua's sideplot with his sister. Then all these arcs will open an infinity of unexpected possibilities for the future, while in themselves appearing with self-contained and conclusive. And Togashi will pass away as he pens the next big arc after the latest big arc.
Tbh, my prayers are simply for the succession war to finish so I can lay off the series in peace.
The dark continent is designed to be yet the biggest, most encompassing arc introducing the most new stuff of all - no way in hell will that ever be finished with Togashi's current pacing. Mind you that DC will be all about the new world and thus will require more complex art, atm he's
mostly just drawing characters and simple rooms and still taking long.
No offense to Togashi, hope I'll be proven wrong, but I think that's just the realistic stance. Even if he should get to starting it, I won't start reading the DC.. can't bear this waiting game yet another time, lol.