Himmler was just a chicken farmer and the sadist who ran the S.S. ! We would never have made peace with him ! His incompetence would have made it easier and sooner for the Allies to win the war ! We would have hanged him anyway ! But he took the cowards way out and committed suicide !
He'd most likely would have sued for peace or some sort of armistice with the Allies early, which he never would have got. Germany would have surrendered earlier, Himmler was not that kind of leader, he lacked strategic thought. He was a bureaucrat,
The Nazis would have lost a lot faster then they did. Hitler was a terrible person but I have to admit the Germans wouldn't have gotten so far without him. Himmler would not be a good enough replacement to help with the war and a lot of his soldiers would buckle under the pressure of the Allied advance and surrender. Then instead we'd be asking questions like "would the nazis have won if Hitler hadn't of died"