It’s amazing to me that Mugabe is still alive. He must have a huge bodyguard. It’s rare in this world where you can predict with any accuracy where anyone will end up, but in his case, it is at the bottom of the river, or at the end of a rope. Those are just the odds.
Since the rest of the population is near starvation, I don't believe anyone opposed to him will have the resources or strength to mount an effective coup. It will have to come from inside his inner circle or from a group external to Zimbabwe.