IOTL Hans Hube's First Panzer Army was encircled by the Soviet 1st and 2nd Ukrainian Fronts in March 1944, marking the climax of the Soviet winter-spring offensive of that year. Remaining cool in such desperate circumstances Hube was able to save his army, orchestrating a breakout towards Tarnopol to link up with 2nd SS Panzer corps.
However, what if the situation had gone far worse for Germany than IOTL? What would be the result if most of 1st panzer army was destroyed, crippling Army Group South?
this had every chance to go to complete shit for germany; manstein and hube were having a bitter personal feud; Hube routinely went over manstein's head to hitler or just did whatever the hell he wanted to the point where Manstein threatened his resignation if he wasn't given a proper relief force to save 1st PAA
hitler in a rare moment of clarity and unbiased thinking (for that period) took Manstein's side in the arguement; told Hube to break out to the west (and to shut up while he was at it) and gave Manstein several very strong armored divisions to break the pocket; which was done successfully
manstein of course was not so deft in the after math by suggesting to hitler that he should be given supreme control of the eastern front; which lead to his dismissal
all you have to do is have Hitler accept Manstein's resignation (maybe clean house with the staff too) and let the command vaccume compel the 1st panzer army's total collapse
this easily shaves 6-12 weeks off the war; maybe more