This is something I've been thinking about for a while. The POD is for whatever reason there is no decision to sortie the High Seas Fleet so it remains tied up in port and there is no mutiny.
Germany's allies fall away in October 1918 and especially Austria-Hungary which capitulates to the Western Allies on November 4th. However, through a combination of terror and apathy, the Imperial System survives another harsh winter. A combination of near-famine via the blockade and loss of other import routes and the growing influenza outbreak further weakens an already-exhausted populous.
On the Allied side, the arrival of the Americans continues to tilt the balance - they bring fresh men, fresh supplies and fresh food to Europe.
Instead of a full campaign history, this is going to be a series of vignettes based on one part of the front but it will tell other parts of the short campaign leading to the final German collapse.