I would have ceded Posen to Poland, and united the new state with Lithuania. Germany still loses its colonies and Alsace-Lorraine, but not the Saar or Ruhr.
Italy gets Trieste and the Italophone districts of Tyrol. Austria retains the rest of what was before the war Cisleithania sans the Czech lands and Galicia. Hungary retains Slovakia and Transylvania.
Croatia, Bosnia, and Banat unite as Croatia, a monarchy under some Italian noble.
Romania gains Bukovina and Bessarabia.
Belgium gets Luxembourg, and Serbia gets Montenegro.
Thus, with the exception of Czechia, Germany is surrounded by somewhat larger and more powerful states.