Well, losing Der Fuehrer would be a bit more than
moderate bad luck, and it could well be argued that if whoever takes over (Heidrich?) has the same war aims, then the chance of France falling would have been even better. Many of the possible ways to cock it up seem to involve simply doing what AH wants.
I get the impression that the Saarland invasion was called of because of advance warning of Russian interest. Given that, Frances best strategy probably was, as in OTL, to wait for the Germans in Belgium.
So Hitler throws the dice as in OTL, gambling on the slim possibility of early victory rather than a holding position. He throws six after six, but the last vital throw fails. The "sickle cut" is late. It runs out of fuel and into trouble. The British counterattack from Dunkirk links up with the French and it is all over within days.
The Germans have surrendered, but most of Poland is still in Soviet hands, and the Finns have just shown that the Red Army is perhaps not as mighty as had been thought.
Hitler has just been spanked - hard. Now what about Stalin?