The Rumour Mill says he is considering retiring if his election call is rejected. He has managed to paint himself into a corner, and split the party. He still has friends, but many enemies. It is difficult to see how he can carry on without breaking the law, or surrendering.
I would favour a National Government like we had in the thirties and forties comprised of the Opposition and Conservative Parties to rule until Jan 31st 2020, if the EU grant that extension.