Barbarossa starts in mid-May instead of late June.
Moscow falls in November 1941 but is recaptured in January 1942, the effort to do so and supply drain weakens Leningrad enough for it to fall in May 1942.
With Leningrad fallen, the Germans cut off Murmansk as a supply route into the USSR and redeploy troops to help take Stalingrad in September 1942 and retake central Moscow in October 1942.
Soviet army forces fight fiercely for control of the capital during the winter but slowly lose to a reinvigorated and now-fuelled German war machine.
By July 1943 the Red Army is falling back to the Urals - a peace treaty finalized that October spares Soviet Asia but leaves European Russia in the hands of the Germans.
Germany relocates much of its industry to northern Russia away from Allied bombers and gains 'inspiration' from various Soviet and loaned Allied equipment, including the SVT-40, T-34, and Pe-8
D-day proceeds as scheduled though progress in Italy and Southern France is much slower, eventually Italy becomes a way to tie down German troops as the breakout from Normandy and Provence face more numerous and better-equipped German forces.
German forces slowly recede across France and Central Italy while Yugoslavia largely frees itself by year's end. Keeping troops on the Urals border in case of trouble with Soviet Siberia, where a bitter Stalin is certainly rebuilding his army, Germany still sinks over half its army into Russia for defense and occupation.
Berlin falls in early 1946 but a rump German state holds out in former Poland, the Baltic States, and Soviet Europe. Only with the fall of St. Petersburg in 1947 does organized German resistance end, many Nazis fleeing to Finland as the Allies parcel out technogical achievements from the Type XXXV Uboat prototypes to the Stg46/Gerat-06(H) rifle to the Z6 computer and A9/A10 missile system et al.
Germany manages to send a man into space on a suborbital reconaissance mission in late 1946 via the Sagner Silverbird, unfortunately due to insufficient heat shielding he slowly cooks alive over Hawaii and the Eastern Pacific on re-entry. They also achieve development of a prototype integrated circuit as well as a robust synthetic polymer/oil industry.
European Russia is returned to the Soviet Union, who invaded in mid-1946, only after the Allies have picked the country clean for any advanced technology. The Iron Curtain excludes the satellite states and Eastern Europe with the US and European Community beginning a cold war less than a decade later.