It will take more battery as you are using ad-hoc wifi between the F and the drive, but I think you will have enough run time (5 hrs) in between plug-ins, or you can always pack a USB based battery.
p.s. it never occur to me to get a 1T USB 3.0 drive with wifi even though I know about them for a long time. Going to order one and will report back sometime next week.
Edited by DrSheep - 9/6/13 at 9:32am