Neither POD really shortens the war that much; the forces that got out of Falaise were pretty shattered and mostly not combat troops IIRC. Taking Warsaw just means the Soviets have to deal with the Poles who don't want to be dominated, while it saves the Germans a HUGE problem of having to fight to take the city back, while then relieves them of having to feed the people there and can use it as a fire sack for Soviet troops. If anything that probably makes the Soviets worse off, as they have to feed the city too. https://en.wikipedia.org/wiki/Warsaw_Uprising