What Modern Nazi Germany would look like today?

I don't think a progressive movement is likely to arise in a victorious Nazi Germany. While the U.S. oppressed non whites the system wasn't built around this fact, and even in the deep south there was always freedom of speech that was respected. Nazi Germany has no problem jailing or outright shooting critics, and the mass killing means there won't be any groups to raise grievances within their empire. As far as your timeline, Britain won't fall. It would take the nazis at least 5 years of uninterrupted building before they have the Air and Naval power to get England, during which the U.S. is probably flipping into full cold war mode. With a land border with the Soviet Union Germany will never have the luxury of a safe homeland. The Soviets can match their industry while the U.S. will undermine both of them abroad. Because of the German threat to the Soviets the nationalists might win in China if the U.S. offers more support, ensuring that East Asia will be dominated, or at least allied, with the U.S. As much as I hate to admit it a victorious Nazi German that survives into the 1990s probably means a much more powerful U.S. as the Nazis and the Soviets know they cannot trust one another, and cannot effectively oppose U.S. interests outside of their immediate spheres of influence.