I have been watching The Man in the High Castle, a show about a postwar occupation of the USA by the Axis. While an Axis victory to this extent is of course beyond ludicrous, it made me wonder about worst-case planning by the Allies.

The Soviets, in my understanding, are not likely to have surrendered regardless of circumstance. The entrenched ideological differences, plus Nazi policies of extermination, plus the centralization around Stalin leads me to believe that they would never have surrendered, but would have fought until serious military resistance was impossible. Did they have plans for that eventuality and after?

Did the Americans have any similar plans in the event of a total defeat? Did the USA make plans for a negotiated peace in the face of defeat, say in the event of the fall of the USSR and/or the UK? Did the government have any contingency plans to respond to occupation?