I keep Duke's body (and his docked tail), short during the summer months and let the hair on his body grow to about 2-3 inches during the winter months. I always keep his face long though.
He looks a bit like Gizmo. A groomer once gave him 'Yorkie' ears although I told her to keep his face long and just trim it up. She said that was the only way she knew how to do Yorkie's ears and well, Duke never went back because she just basically shaved every part of his body.
That's been well over a year and several haircuts though.
Also, Duke has always had long hair on his ears so he is used to it. If his hair on his ears get too long they will droop and I've heard if they are used to having short hair on the ears then long hair will make them droop.