How would Germany use a reduced but still substantial surface fleet in 1940?
Short answerIt would probably disperse the ships around Europe and use them as a fleet in being.
NotesThe surviving ships would probably be deployed much as Germany used its historical surface fleet. Dispersal would preserve the force rather than risk every ship in one decisive action. Their existence could still compel the Allies to guard routes and maintain counter-forces. Survival and strategic pressure matter more here than concentrating the remnants into a single battle fleet.