Ok, if everything goes as IOTL, the French barons as well as the King of France (Philippe V ?, Charles IV ?, Philippe VI ?) will never agree that Joan marries a foreign prince (even if Edward is half-French by his mother and speaks French). I think that the reason behind it, was that people in her time were conscious that Joan had a strong claim to the throne and that she could be a potential heir to the throne after the death of her brother (John I) and even after the death of Charles IV! So they didn't want Joan to probably bring France as dowry to a foreign King. That is why once Philippe V was on the throne, Philippe of Évreux married Joan in order to appease the barons' fears .
Moreover, Joan was a heiress to Navarre, Champagne and Brie and extensive lands in Northern France and had an ally into the powerful duke of Burgundy, Odo IV. If Edward marries her he ends up with multiple claims from the Pyrenees to the the Channel (as Emperor Constantine said) but also with problems with the French, if he married her before 1328. But even after that her claims could be seriously considered, if you look at her son Charles who managed to put Normandy in a state of rebellion against the Valois. Thus Edward will be looking for a bunch of problems .....but that could make a terrific timeline.