They wouldn't have an EMH and not have a bus running early enough to get the guests there. So of course there will be a bus running that early. If you can get on the very first bus you'll be good. The big problem is, how do you get yourself to the bus stop in time for the very first bus of the day, when there is no way to know exactly what time the first bus will come to your bus stop. Well, the best way is to get out there about 5:45 AM and wait. I don't know about you but the last thing I want to do that early in the morning is spend an unknown length of time waiting on a bus. Not when I can spend less than $10 to ride Uber in about 20 min, with only about a 5 min wait. Time is precious to me in the mornings at Disney, since less time waiting for a bus means more time sleeping. I gladly pay $10 (or more) to sleep another 30, 45 min instead of waiting for a bus. We've gotten to where we almost always take Uber for park opening now, simply because I am in control of my wait time, or at least much more in control.