You know, i keep thinking that they could do one last "ultimate" terminator movie. We already have back and forth timetravel, why not add different universes to it? some kind of Multiverse Terminator. Bring all the Terminator timelines together and have one final huge movie. After that you could easily go with the future war and dont need to rely on the characters or the same story over and over again. You could go all out after that. But one last movie with Sarah Connor, John Connor, Kyle Reese etc together.