Thanks for all the fun and useful answers.
@croach, you are right about not overthinking all this... Did I mention that I had trouble pacing myself?
But it is part of dreaming, exchanging with other Disney runners and will probably make the experience more pleasant in the end.
The more I go, the less I want to carry so yes, phone and one pack of some kind of fuel will be ok. Phone is huge so, yes, I'll carry it in my hands for parts of the way... And now I know when (approaching the parks), thanks
@roxymama!