Uber victory
I don't know how you get to German uber-victory and conquest of the US. I think that you probably could get to Germany knocking both the British empire and the Soviets out of the war. It would take luck and bad choices on the part of their enemies, but it's probably doable.
The Brits: Have the weather clear up so that the Germans attack in France in late March/early April 1940 instead of May 10, 1940. Assuming substantially the same results in France, and assuming that the invasion of France causes the Germans to postpone the invasion of Norway, that means that by late April the Germans are at the Channel with Chamberlain still in charge of Great Britain, the British a month and a half's production weaker in fighter planes, and with the Germans still having a working navy. (They essentially didn't for a while after Norway).
The British probably don't have anywhere near as many people evacuated from Dunkirk because the historic evacuation was partly dependent on a peculiar weather pattern: Clouds over the evacuation beaches, plus good weather in the channel. Fewer soldiers evacuated and Germans at the channel with an entire summer to try to put together an invasion might cause Chamberlain to do something stupid like seeking an armistice. That's not the most likely outcome, but Chamberlain didn't exactly make the brightest of moves in relationship to Hitler.
The Soviets are a bit tougher, but give the Germans a little more time in 1941 and they might have been able to take Moscow. The Balkan sideshow cost them a little time (no more than a couple of weeks), but more importantly it put some fairly substantial miles on the participating German Panzer divisions, which made logistics even more iffy than they already were. The Balkans campaign used up fuel, spare parts and ammo that would have been useful in the summer of 1941. Apparently it also meant that two of the German panzer divisions that were supposed to attack out of Romania weren't ready to go until a week or two later than the jump-off, which was part, but not all of the reason the Germans didn't do as well in the south as elsewhere, which was part of the reason Hitler felt that he had to divert south rather than going directly for Moscow.
The best option for the Germans in Russia would be for Stalin to sue for peace in order to keep a semblance of power, and becoming essentially Vichy written large. I don't think that Stalin would offer that, or that the Germans would accept. Barring that, the best the Germans could hope for was for the Soviets to become sort of a Nationalist China written large--still independent and still in the fight, but with the part of Russia that generated great power in German hands. Getting even there would take near-perfect German decision-making, a few more Soviet missteps and no Balkan expedition. That much is not impossible, though it is very unlikely. Getting to a successful Axis invasion of the New World is very difficult.