Probably the most plausible further loss of German territory: Czechoslovakia gets Lusatian Sorbia as compensation for the loss of Carpatho-Ruthenia to the USSR (this is more realistic than Germany losing all of Saxony, as the original post proposed; it can be defended on national self-determination grounds).
In OTL, the Czechs did show some interest in the idea, but Stalin was opposed to it. According to Karel Kaplan, *The Short March: The Communist Takeover in Czechoslovakia 1945-1948* (New York: St. Martin's Press 1987), pp. 24-25:
"The Czechoslovak government expressed interest in annexing territory
inhabited by the Lusatian Sorbs in the Soviet occupation zone of Germany.
Prague did not demand annexation officially, but spoke out as a defender
of the smallest Slavic people and supported the Sorbian national movement,
which strove for annexation with Czechoslovakia. In particular it was the
Lusatian Sorb National Council in Bautzen which turned to the Prague
government, Benes and Stalin with the demand for annexation. The Ministry
of Foreign Affairs cooperated with the Lusatian National Council and
forwarded its memorandum to Zorin in Moscow. Kopecky [the Minister of
Information] and Nejedly [the Minister of Education and Culture] urged on
June 8, 1945, that the Czechoslovak government insist on the annexation of
the Lusatian Sorbs. The government decided to request the occupation of
Lusatia by its army. The Society of Friends of Lusatia renewed its
activities in Czechoslovakia and together with the Slavic Council
organized demonstrations calling for annexation. All these actions evoked
no significant response in the international arena. The Great Powers did
not reply to memoranda and the occupation of the territory by Czechoslovak
troops did not take place. An attempt by representatives of the National
Council to bring up the Lusatian Sorb problem at the Potsdam Conference
met with similar results. They had hoped that Stalin would present their
plan, but he was silent on the matter. Even after the conference, organs
of the Lusatian Sorb national movement tried to achieve a separation from
Germany, but without success.
"The attitude of the National Council and the Prague government toward
Lusatia's secession from Germany was not in conformity with Soviet
interests. In June 1945, in response to an inquiry from Stalin on the
Lusatian matter, [Prime Minister] Fierlinger termed the affair
'delicate.' In reality, Moscow had no intention of ceding this German
territory, where its own army was in place. Moreover, within the
framework of its conception of a central administration of Germany, Moscow
was opposed to splitting up its own occupation zones. In Lusatia, the
Soviets oriented themselves around the Domowina, after the National
Council the number-two local and traditional organization, which Moscow
recognized as the sole representative of the Lusatian Sorbs. Control of
the Domowina was gradually taken over by Communists, who proceeded to
claim that the rights of the Sorbs would be best ensured in a democratic
Germany. German Communists, whose stand reflected Soviet intentions,
characterized the separatist tendencies as reactionary. In the autumn of
1945, the Soviet occupation authorities halted the activities of the
Lusatian Sorb National Council. For the first time, the Prague government
realized that its intentions were inconsistent with Soviet plans for a
central administration of Germany, which were based on the Soviets' anti-
German attitude, and ceased its attempts to ensure a permanently weak
Germany. As soon as Prague woke up to the fact that it was out of step
with Moscow, around the end of 1945, it lost interest in the fate of
Lusatian Sorbs."
Still, one wonders: Granted that in 1945 it made sense for the Soviets to prefer to keep Sorbia as part of their occupation zone, rather than give it to Czechoslovakia, where they were about to withdraw their troops, and where the government was not yet fully controlled by Communists. Still, after February 1948, might not Stalin change his mind? After all, Czechoslovakia by then had come under Communist control, and Stalin might in this way (a) compensate it for its loss of Ruthenia, and (b) assure that if ever he did have to accept a unified non-Communist Germany, at least that one area would not be part of it? (The fact that by the 1940's even the most heavily Sorbian areas of Germany had a substantial German population could be "solved" by ethnic cleansing; indeed, as part of Czechoslovakia, Sorbia would presumably be subject to the Czechoslovak policy on expulsion of Germans, which after all had been originated not by the Communists but by Benes. A few trusted German "anti-fascists" might be allowed to remain. And of course a lot of Germans in the area might suddenly re-discover their Slavonic roots...)
