My loadout is a whole lot less than that when I go to shoot motorsports events. What are you really going to need 2TB of storage on the go for? I'd do a test run of how long it would take to complete an SD -> iPad -> HDD transfer to see if it's workable for your purposes.
My rule of thumb for photo/video-heavy events is 1 fresh card per device, per day. At the end of the day, each card gets its contents dumped onto my Surface Pro 3 before being labeled and set aside. Once the trip's over, the files are backed up remotely and the cards wiped for reuse.
As for entertainment purposes, I usually keep a micro SD card in the SP3 loaded with audiobooks and podcasts, a season or two of a TV show, a couple of movies, and a ton of comic books. It's plenty for me, but YMMV.