Simply put, what if Operation Bagration for some reason failed to achieve any of its objectives? Let's say Bagration's fate is the same as Operation Mars' fate 2 years previously, a bloody stalemate between the Wehrmacht and the Red Army?
there are a number of pods that would have to happen to make this possible.
the biggest one has to be having the kursk offensive called off. not sending the panzers on a death ride will given the germans more strategic reserves to counter russian offensives. secondly they would have to construct a true east wall which given the size of even army group center's front is borderline asb
assuming they could somehow give the russians a bloody nose in bagration with a smart strategic defense its possible the russians could sue for peace. by late 1944 or 1945 even stalin had reached the bottom of the barrel in terms of manpower. if they take terrible losses in bargration they may not have the bodies to extend the war further.
imo by 1944 the germans are done you need much earlier pods to make that happen