Not the best example but Nicholas II was still on the throne in the Fourth Season episodes of Enterprise set during an altered WWII, and because the Nazi's found the Romanovs less unpredictable, they were able to roll on through and make a beach head in America after conquering England.
But that episode was shit as far as historical accuracy goes. First off, to imply they had a shot in hell of invading America is one. Second, to imply that Hitler wouldn't have invaded the Soviet Union is another. I think the airplanes are at least OK as far as historical accuracy goes, but I'd have to doublecheck.
Operation Sea Lion never had a snowball's chance of succeeding. They needed to establish air superiority over England and they were simply unable to do that. They could have conquered all the way to Kamchatka and it wouldn't have changed the fact that Britain was outproducing Germany in fighter planes and their planes were out-surviving German planes.