Eisenhower dies in a plane crash during the transfer of command from England to France, around August/September 1944. To keep political harmony within the Allied Armies, Bradley is promoted from 12th Army Group to SHAEF, and Patton is moved up to replace Bradley. Everybody knows that Patton was the compromise choice to replace Bradley, and it is done over Bradley's objections (due to Patton's reputation and actions in previous campaigns, Bradley did everything possible to prevent Patton from being promoted further in terms of commands).
Montgomery complains, but Churchill keeps Montgomery where he is (in private, Churchill is aggrivated by Montgomery, whom seems to have a lard bottom. A post-war comment by Churchill on Montgomery, "I was certian he was trying to cross Europe on the cheapest possible tour, taking his time to save money.") Patton takes 12th Army Group and molds it more into his image.
What happens next?