[whpalmer4]

Why not just use the USB cable and iTunes to move the file directly to the MBP when you get home, and avoid all the fuss? Not clear to me why you want to export the work-in-progress as the train rattles along. If you need to save multiple versions, just duplicate the document in the document chooser and continue on. If you are truly concerned about security of the data (as opposed to being concerned about following the letter of the law), skipping the part where you broadcast it to the world on the way to your hopefully secure server seems like a good thing.