There is always a simple solution to a vexatious problem. All it requires is that sufficient ANC MP's follow their conscience and refrain from voting - called abstention - this would solve the 2/3rds requirement. Whether it will happen is another matter entirely.
Personally I don't think anything will happen until the the municipal election results are in, and then the ANC will recall Zuma as they can lay the blame at his doorstep for their poor showing. Its a more acceptable way of exiting Zuma as the phrase "the people have spoken" takes on relevance