Nazi invasion of America

[The Mikado]

Implausible for all sorts of reasons, not least where the hell Germany could've gotten the manpower to keep all of Europe under occupation AND the United States, once you get to the already insane "Germany successfully defeats the United States."

Germany's best case scenario involves continued American neutrality towards them for years coupled with a successful (insanely risky, but Hitler had a gambler's heart) invasion of Britain followed by a successful invasion of the USSR, which is a long shot as the Soviets grew stronger every year but is possible to imagine under the right circumstances.

America was always going to eventually go to war with Japan, Germany staying out of that war would've been a necessary prerequisite to any hope Germany and Italy had for a new European order. You might end up with a very different and far darker world where the US has defeated and occupied Japan but all of Europe and North Africa is under Nazi domination either as puppet allies or military occupation. This would leave the US as the great power of the Western Hemisphere and the dominant power in the Pacific Rim along with a friendly Nationalist China and a puppeted rebuilt Japan (and the Philippines still an American colony or, if released, a very friendly one), with the former French, Dutch, and British colonies in South Asia/East Asia/Southeast Asia/Oceania going independent from their dominated and forgotten metropoles.

This is about the most Germany-friendly scenario you can imagine and it's a horrifyingly grim one, but Germany would be strapped to the limit with its manpower to just hold all of that territory. Ukraine plus most of European Russia is a LOT of turf to occupy against incredibly hostile local populations, and Germany would have still lost an obscene amount of soldiers even in this winning scenario.

The British government in exile in either Canada or Australia would have horrible tensions with the locals, too. That'd be a fascinating dynamic, a sort of updated to modern times take of when Portugal's government in exile had to move to Brazil in the Napoleonic Wars.