I eat breakfast before leaving the house, but in a pinch I can handle my 30min commute (and it's got a rather big hill) without. I just hop out the door. No bottle needed - no time - I drink tea when I get there.
I find having a little something in the stomach is better than nothing.
I also found I can run within 10 minutes of getting up, but half a glass of milk will help the stomach stay calm.

30min will not deplete you. You have dinner in you from the night before, --> should have enough glycogen unless you are depleting that constantly; but your blood sugar is rather low in the mornings.
I'm not one for bars. These are for rides, not food...

Eat breakfast, absolutely, people who eat breakfast are healthier. I find the commuting actually makes me less hungry mid-morning.