Like I said it is a messier solution but it would work.
A terabyte could probably be obtained in this fashion in a few hours rather than a few minutes.
It could work but Snowden was clever enough not to draw attention to a large download by splitting it up over about three months.
He was downloading from the start of his employment at Booz Allen.
As a system admin he could easily sector a hard drive and password protect the sector he was downloading to.