The success of Operation Sealion was completely impossible, but what if Hitler had tried it (and failed miserably)? What would be the effects of an earlier end to WWII?
germany loses 4-8 divisions and the LW and KM get ground down
however the British might be less inclined to dispatch ready troops to the med for fear of renewed invasion attempt (not a rational fear but it would exist)
if Hitler accepts the loss and moves on losing 4-8 divisions isn't a big deal... the army lost 22 divisions at stalingrad without giving up or turning on the government