If Barbarossa succeeds in 1941, meaning the Soviets are defeated immediately prior to, or concurrently with Pearl Harbor there are a couple ways the question can be answered.
1. The Reich never declares war on the U.S. and effectively presents the British with a fiat accompli. There would be almost no reason for the Reich to continue with the War against the UK, and utterly no reason to continue with USW. Both the U.S and UK will have a more pressing set of concerns in the Pacific and SW Asia. It is one of the few scenarios where it is conceivable that Churchill would find himself outflanked by events, especially if the Reich offered very good terms.
As an example of terms that might just be too good to refuse: Removal of Wehrmacht forces from Belgium, the Netherlands and Norway with the three countries effectively being demilitarized. Formal recognition of Vichy France with a pledge of non interference and a binding guarantee that French colonial rights will be respected (this would piss Mussolini off to no end, but with the land war over, the Reich needs Italy like it needs an appendix, and Hitler can allow Mussolini to build his new Roam Empire along the Adriatic and Agean). Removal of Wehrmacht forces from Africa. Return of all Commonwealth PoW. Compensation for damages to property in the UK. British recognition of the Reich's area of influence in Europe and a free hand there.
The key to this is that Hitler really didn't WANT to fight the British, not in 1940-41. He didn't want to fight the U.S. for at least a generation, in actual fact any Reich decision to attack the U.S. would have been in the hands of his successor. It would have taken the Reich 40 years to really digest General Government and European Russia (I am assuming that the Reich follows the AA Line plan for post war occupation of the USSR) which was Hitler's real goal, destruction of the Slavs, the Communists, and the various ethnic groups his perverted beliefs found unworthy of life.
Churchill would be faced with the problem of continuing a war against effectively ALL of Europe, with only the Commonwealth for support (and Australia & New Zealand are more than slightly questionable with the Japanese advancing into the DEI) and doing to save what? The Soviets? How much of the British electorate is going to fight for years to save the friggin' Bolsheviks? The Jews? Antisemitism wasn't isolated to the Reich, the fact that London wasn't herding the Jews into enclosures doesn't mean they were loved, same goes for the Roma.
Without USW (and especially without the Reich declaring war on the U.S.) why would the U.S. even consider fighting the Reich while the Japanese are killing Americans all over the Pacific after their "Dastardly Attack". American votes wanted Hirohito's head on a pike, not Hitler's.
In this scenario you wind up with a Cold War that lasts as long as the Reich sticks to the Eurasian mainland and only fights the Anglo-Americans in the economic arena. Figure the Nazis to mismanage the Reich into OTL 1989 USSR conditions by the mid-70s.
2. The Reich still declares war on the U.S. and chooses to continue to fight with the UK. This is close to AANW, except it is unlikely that the WAllies manage to keep the Bomb under wraps without the active, if unfriendly, assistance of the KGB (in AANW the KGB was much more motivated by screwing up the Reich than helping the WAllies). If both sides have the Bomb you wind up with an unending series of proxy wars and a raging war at sea with no real hope of invading Europe. The sort of massive fleet needed to kick in the door constitutes a perfect target for a nuclear weapon and given some time, the Reich doesn't even need to get in in via an aircraft, submarine or even an a much improved missile, it can be delivered by coastline based torpedoes and large railway guns and even towed artillery (the U.S. had 280mm artillery nuclear warheads by 1952 IOTL). Nuclear weapons made invasions like Overlord or Iceberg a thing of the past, unless the target country lacked a nuclear deterrent.
If the WAllies manage to keep the Bomb under wraps and the Reich follows its historic lack of interest, then the earliest you could see a serious attempt to land would be around 1950, possibly later. It would, as was the case IOTL, only be possible to even attempt a landing after the Luftwaffe was rolled back. Without the constant losses in the East, and with the access to Soviet materials (along with the added strategic depth that would make practical bombing of Reich military industries impossible until proper, large scale air-to-air refueling was developed) it is difficult to see how the WAllies manage to knock the Luftwaffe out of the War in less than six or seven years. Even with that sort of lead time the WAllied ground forces will have serious problems unless they have, somehow, developed a mature armored warfare doctrine (not to mention sufficiently advanced vehicles) once the get more than 10 miles inland and leave the protection of the gunline, especially at night. I would frankly doubt that the WAllies would develop a useful doctrine, nothing in the Pacific, SW Asia, or even North Africa will prepare them to face the sort of heavy armor that the Heer was already developing in late 1941 (even in a rapid victory Reich designers would take the lessons of the T-34 and KV-1 into consideration) when follow on generations of vehicles are brought into service.
The wild card here is if the Party follows through with its half developed plan to replace the Heer with a more politically reliable SS based force and if Hitler gets rid of the General Staff concept in favor of his own military "genius" and true believers in place of merit promoted professional senior officers. If the Heer continues with the the thoroughly professional officer corps and long service, well trained and developed NCOs the Reich is a vastly more dangerous opponent than if it has evolved into a politically orientated, loyalty test promotion based, regime protection force.