Don't forget that the German navy took a pounding during the Norway invasion, and the had little surface ships left...
The Royal Navy, on the other hand, had a substantial fleet in home waters, and would have had little trouble stopping any sort of makeshift German invasion attempt,
The RAF ensured that the Luftwaffe could never achieve sufficient air superiority, to protect all those flat bottomed barges being towed slowly accros the Channel.
.
So as long as Churchill said no to any peace talks, Hitler could say what he liked, but the German navy simply didnt have the capability to launch any kind of invasion..
The romantic idea that "The Few" saved Britain in 1940, is only partly true...
The Royal Navy deserves as much credit..and i say this an an ex member of the RAF!