you can copy them to the external and send them back when done.

i do this with other big file games so i did not waste my internet cap of 170 gigs when i did have the cap. so a 14-30+ gig game would be just to much each month. so i would copy the files. when done copy them back and let the game update what it needed to. which is can be as low as 40 megabytes as it is just checking and seeing if the files are not out of date.