> Had France "fallen," EU would have been toast.

Actually it wouldn't have been. What most people will discover (though I think most French nationals are well aware), is that the president has very little power in France unless he also controls the parliament. Which Le Pen was guaranteed not to achieve. And which will still be a long shot for Macron. Had Le Pen been elected, she would have been reduced pretty much to the role of a queen of England. With nuclear firepower but very little means to create trouble in the EU.