I have little doubt that if Hitler had access to something like MAD, he would have used it as the walls closed in
Hitler was mad enough to have wanted it, but I very much doubt his senior officers would have gone along, there was a wish for surrender to take place in some quarters prior to Hitler committing suicide. There were those planning as early as 1938 to get rid of Hitler as they had no wish for another world war. The apparent aim of the bomb assassination attempt was to wrest political control of Germany and its armed forces from the Nazi Party (including the SS) and to make peace with the Western Allies as soon as possible.