I was thinking about this earlier today.
If the Burgundians, in the midst of the Hundred Years War had managed to play both the Dauphin and English against eachother, was it ever possible for Philip or Charles to see themselves crowned as King of France? If they do, what happens from there? Let's assume the direct Valois (including the Duke of Orléans), south of the Loire, end up going extinct for the purposes of this question.
Charles ends up leaving Mary as his only child. I know Salic Law prevented women from holding the crown of France, but Salic Law had only been established in France almost a century earlier, to prevent the English from laying their hands on the crown through Isabella Capet. French fiefs generally did not follow Salic law, either -- women were generally allowed to inherit fiefs and transmit them to their heirs, such as Suzanne of Bourbon. It was only lands attached to the royal domain where the lack of a male heir meant they rejoined the crown -- such as those Burgundian fiefs on the death of Charles.
With the direct Valois line dead, and Charles leaving Mary, with no other viable candidates... is it possible the French might allow her, in a time line like this, to become their Queen? She generally seemed to be a rather clever woman at the time. Perhaps a marriage could even be married to a powerful French magnate (The Duke of Bourbon, or even Brittany?) to secure her rule, the two effectively ruling as co-rulers? Or was Salic Law too entrenched at this point for it even to be considered?