I think that the conditions for the scenario are implausible. Germany could not conquer Britain and, even if they managed to reach the A-A line, I doubt that the Soviet Union would surrender.
And even if they managed to do that, the local populations would resist. It would be a situation of...
What do you think of these maps?
https://www.deviantart.com/quantumbranching/art/For-All-Time-2009-220141264
https://www.deviantart.com/quantumbranching/art/For-All-Time-2050-246663118
My guess, the Soviet Union in part to recover their former glory and in part for opportunism will enter in Pacific War (which anyway will go much worse for Japan than OTL thanks to having the US concerned only with them), taking Manchuria, all Korea and perhaps even Hokaido.
IIRC Stalin...
About that crazy objectivist american government in Guantanamo.
Could give us a more detail description of their (false) view of the world in which they told at their population that live in order to keep them in line?
I think that Superpower Empire is too optimistic.
I think the Chinese simply wait until the Nazis were so weak suffciently (by 1959?) And take all or most of Russia. Then I think that relations between China and the rest of the world would be somewhat cooler.