I hate to say it, but a coup may be the only realistic option at this point.
Well, by going full-authoritarian even an elected government loses its legitimacy. But the only coup I could possibly be looking with hope toward is the one to quickly restore full democracy and withdraw to the barracks. Otherwise it's bad replaced by possibly worse.
The Venezuelan officer corps is dominated by Chavistas. The top brass de facto already rule the country.
All it takes is a disaffected colonel or two...
No, not if the bulk of the army is against them. Even if succesful at first (which is very unlikely) they would quickly be removed.