Turns out the HTC One DOES have a microSD card slot (But not for us)

[Djnikkofb]

or get a 1tb Seagate wireless +Wi-Fi hard drive. transfer over its own Wi-Fi

inscribed by Droid DNA/Nexus 10 now Free

 

[drago10029]

Kinda defeats the mobile purpose though, to each it's own I guess.