Well, I never imagined Robert Mugabe's new survival gambit would be just to pretend it wasn't happening. But it does permit us to answer the question of just how small a state can get and still function; to be clear, I don't mean a state in the juridical/diplomatic sense, but rather in the political, realist sense. The Grand Master of the Knights of Malta's house in Rome has some diplomatic privileges, probably because nobody cares enough to change this. But Mugabe's continuing occupation of the office of president of a political entity called "Zimbabwe" certainly does have consequences; specifically that while he's in there no-one else can get in. This has fairly serious negative consequences for Zimbabweans in general, and also for anyone who believes in the principle that tyrants should be held responsible, as his residual occupation of the presidency gives him non-trivial bargaining power.
As far as we know, he's closeted in Government House with a small group of officials, notably including military leaders, political thugs, and the governor of the Central Bank, who has the keys to the remaining foreign exchange and knows how to start the printing press. Noises are being made that the military will not "fight the people of Zimbabwe over election results"; that might mean they would fight over something else, or else define the targets as something other than the people of Zimbabwe, or it might mean the army is unwilling to take any action.
Other than, presumably, protecting Comrade Bob himself. A few weeks ago, it emerged that the political entity known as "Chad" actually extended precisely to the radius of action of an Mi-24 helicopter based in N'Djamena. But now, it appears that "Zimbabwe" in the political sense consists of Government House, the central bank, and a small field of fire around them, and the numbers to Robert Mugabe's bank accounts. Not even the top level domain or the corporate or aircraft registry.
The obvious answer to this is secession; make local arrangements, set up a shadow administration, and simply ignore them right back.