I know this is highly unlikely and risky for the Allies. But..
What is the best possible location to place an amphibious invasion of Germany within Germany territory? I suppose the time-frame would be between operation overlord and the German surrender. I know certain people debated on the other German location for a hypothetical Allied invasion but still..
It doesn't have to be a primary invasion, it could be a small secondary landing, maybe after the Normandy invasions to try and get deeper into Germany and join up with the Soviets from the North or even beat them into reaching Berlin (though that would be stretching it).
Aside from spectacularly failing, what are other possible effects?