Okay. Let's assume Stauffenberg simply uses more explosive, Hitler (and some other folks) die, Goerdeler forms his new government*.
*I omit the role role of the SS for the moment.
What the new government knows on the 21th of July 1944:
- Germany has lost the war on both fronts
- the Allies want an unconditional surrender
- Stalin, who was about to sign a separate peace until 1943, is not going to let the Reich go away after Bagration
- the war criminals, as long as their are still alive, are to be judged
So there is no real chance to end the war with a victory or to gain a beneficial peace/conditional surrender.
But one have still to remember that the conspirators are, in their majority, reactonary/conservative. They more or less hate communism and are willing to work together with the western powers. Here is my thought:
Roosevelt might stand on an unconditional surrender, but Churchill despises the Soviet Union as much as the Nazis. He is conservative like Goerdeler and the other 20th July folks, and even if he won't accept a white peace with the German Reich, I'm pretty convinced that he would accept a harsh peace securing Poland's and Yugoslavia's eastern borders against "evil communism".
Such a peace treaty could include (based on the OTL demand of the conspirators):
- Germany army leaves all occupied territories in the west (including Alsace-Lorraine)
- Germany has the right to continue defense in the east
- reparations?
Your thoughts?