If Britain is subdued (however you want to interrupt) early on then maybe Germany never lands troops in North Africa. They leave that up to the Italians while they prepare for Russia and figure out what to do with Britain. Pearl harbour happens on time. They sweep through South Sast Asia riding tandem war elephants made of luck. Barbarossa happens in May but doesn't go as well. The quick defeats of the Wallies will not go unnoticed and some number of troops have to be stationed Britain. That's not even considering that this could be a successful SL POD so the Germans have either less planes or tanks.
America invades Iceland, but then takes the southern option. Landings in north Africa, then islands in the Mediterranean, then southern Europe. At this point this aren't looking super good for Germany. This is when Ireland can play it's geography card for the most bang. They say all of Ireland or invade. We say Ulster or we invade. Ireland has a pretty small population and where are they getting weapons?
Or maybe the B-36 is rushed into production and at this point Americans would rather nuke and go home.
Of course, US landings in Africa and around the Med depend on being able to actually access the Med. That means Gibraltor. With the UK out of the picture, why wouldn't Spain grab Gibraltor?