Well, in that case if he has any progeny, the oldest one inherits Navarre. In this scenario Philippe le Bel is still alive so he basically becomes the "guardian and protector" of his grandchild. I also suppose that you will still have the Tour de Nesle scandal, so the Iron King will make sure Marguerite de Bourgogne never becomes Regent for her son/daughter, due to her scandal/disgrace. It could stir up a conflict with Burgundy if the King of France denies Marguerite's right of regency or access to her child. This child could have claims over Champagne as OTL Jeanne II of Navarre pushed them forward together with her husband Philippe d'Évreux, ( Jeanne did eventually renounced to Champagne in exchange of Angouleme, Mortain and Longueville, but she later exchanged again Angouleme for estates in Vexin). If the child is a boy, we are likely to see a personal union (France-Navarre). If it is a girl, I believe there is going to be the same talk about female succession as in 1316, and a lot if Philippe of Poitiers is around.Navarrese people will surely take up the occasion to reclaim less interference from France in their home affairs.
As you see it all depends about how things are in France when Louis I of Navarre dies. I built these scenarios assuming everything except your POD happens as OTL.