My 3 has more range than my S which has been to LA several times. What's the scare about stopping more than once? There's no penalty. Superchargers are usually open and near the freeway, and most of us appreciate a bathroom break and a bite to eat after three hours of driving.
And why is everyone worried about making the trip 20 minutes faster? Maybe leave the house a few minutes earlier? I don't think they pass out any medals for making the trip in under 5 hours, and driving the car, or watching it drive itself, is really rather entertaining.