Well i think the Option to conquer Britain was not Lost totaly in 1941, if Hitler didn't would go to war with USSR, giving more resources and stay on Focus in Britain will undoubtedly led to a realistic Chance of neating Britains Homeland.
Any Peace Offers from that point, that would restore the Western Countries without them needing to fight for it (UK, France, Belgium, Netherlands, Luxemburg, Denmark, Norway) as sovereign States, could not have been denied by any prime Minister of Britain in the World.
Poland would have been lost for sure, but even in this Light there would be strong arguments against keep the Fight when the above conditions would have been present.
But it is always the same Story, People (Hitler and his Nazis) try to bite more then they can Eat and fail miserably at it.