To claim that anyone’s Brexit strategy is in crisis is to misunderstand what a strategy is. It is the goal that you have decided to reach.
Britain’s strategy in World War II was the unconditional surrender of Germany – everything else was tactics. Hulk’s strategy is “Smash!”. Britain’s strategy with respect to Brexit is: “Thank you, it’s been great, we’re leaving. Maybe we can do lunch some day?” Everything else is simply tactics.