Well, Winston Churchill became prime minister within hours of the Nazi's invading France. That was quite a tough one.
All Teresa May had to do was tell half the public they were idiots, keep us in the EU, preside over a growing British economy and tackle her raison d'etre of bringing people out...
So I'm guessing this is her strategy to keep being elected, stumble around with interminable transition periods so that we're never irrevocably out and she stays as PM