What about having Prince Louis (born and died March 1324) survive child birth?
As grandson of Henry VII, Holy Roman Emperor, he will have allies in the East and could strike a claim for a Capet Holy Roman Emperor, similar to his father.
He would be 4 years old, if Charles IV died same as OTL and would need a regent, which could come in the form of his older half brother Philip, his uncle John of Bohemia, or cousin Prince Wenceslaus (OTL King Charles IV, HRE)
Possible wife:
- Isabella of England, eldest daughter of King Edward III of England and Philippa of Hainault. This could appease Edward who was nephew of Charles IV and inherited a claim to the French Throne, through his mother Isabella of France
- Joan of England, three years older then Louis, younger sister of King Edward III of England, as youngest daughter of Edward II of England and Isabella of France. This marriage would need to be by proxy before the Treaty of Edinburgh–Northampton
- Blanche of Navarre (OTL second wife of King Philip VI) She belonged to the House of Évreux, a cadet branch of the House of Capet
- Eleanor of Portugal, daughter of Afonso IV of Portugal and Beatrice of Castile, connects France to the Iberian region.
- Constance or Eleanor of Sicily, both daughters of Peter II of Sicily