The Crown Prince was more realistic about Germany's fate than others in Germany. On August 16th 1918 when there was a high level meeting of Austrians and Germans where the Austrians basically said we need peace "now" or were doing a separate peace and we should initiate a call for negotiations. Germany put them off hoping that an Allied setupback on the western front would help their negotiating position. Of course that didn't happen and the Salonika front collapsed in September, but if the Crown Prince was in charge by August 16th maybe something could be arranged.
So lets say a Crown Prince run Germany agrees with the Austrians and sends a call through the Netherlands that they wish to negotiate and are willing to evacuate France, Belgium and end submarine warfare as a preliminary to any negotiations. Allies accept this as a basis for negotiations and after 5 days present the following terms:
Possible terms:
1) Germany evacuates France and Alsace Lorraine and Belgium doing no demolitions or setting no booby traps, completed within 30 days.
2) An immediate end to submarine warfare.
3) An immediate cease fire on all fronts.
4) Immediate surrender of all vessels (including submarines and destroyers) currently in Zebrugge and Ostend. (Crews repriated back to Germany)
5) Immediate surrender of German forces in East Africa (Soldiers repriated back to Germany)
6) Austrians to evacuate Italy to 1914 boundry plus evacuating the port of Trieste within 30 days.
7) Austrians / Bulgarians to evacuate Serbia, Montenegro, Rommania and Albania. Central powers still allowed use of Danube for non military transport during cease fire (all within 30 days).
8) No more advances in Russia, but Central Powers allowed to maintain control of this area for the time being.
9) Ultimate peace treaty negotiations with all parties to begin in the Netherlands after those 30 days.
With her military still intact if negotiations fail, Germany agrees to these terms.
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However if the Crown Prince were to take over later in this ATL, once the Allies have broken through at Salonika and broke the Hindenburg line I can't see it making much difference really, the Allies are in a position of strength which they are not going to give up regardless of German politics.