But Hitler had the entire British countryside mapped through a youth spy network in the 1930s to prep for a massive invasion. Once occupied, he wanted to fold them into a United Europe. I don’t think I have never come across any source that has claimed that he thought he would achieve peace in Britain without invasion, although I admit it is an interesting notion.
The Wermacht slowed down because they had outrun their logistical supply line.
Also, on whether Hitler is dumb enough, well he did order Guderian to stop 15 miles from Moscow and turn south, basically giving up a certain victory before winter even set in.