To turn off GPS tracking for the Workout app on Apple Watch Series 2: On your iPhone, go to: Settings > Privacy > Location Services > Apple Watch Workout > select Never. I believe the GPS is only active if you are in 'workout' mode when NOT connected to an iPhone. (could be wrong) however you can set it to never. This should give you theoretically 10 hours of music playback. I'm sure there is a toggle to turn off LTE as well. but i can't confirm that yet. hopefully apple posts a help doc soon.