I would do it even if he would leave next year. Think about it, with our youth, defense, and coaching we'd run through the East no problem. Put Smart, Bradley, Crowder, and Amir around Lebron, and that's as lethal of a defensive unit as he's ever had. Put IT, Bradley, Crowder, and KO around Lebron and let him penetrate and kick, and that's as good of an offense as you'll see in the Eastern Conference.
Hell, given our defense and our decent matchup against Golden State, I say our team with Lebron has just as good of a chance as any other team in the league right now at knocking off the Warriors.
It's amazing just how much difference Lebron would make if we had him. Though I will say, he'd be an absolute perfect fit on our team given our philosophy and the range of excellent defenders we could surround him with, especially because outside of IT we have no other ball-dominant players.