Filling a 500GB Bolt to force use of External Drive?

I'm patiently waiting for my Bolt. I'm planning on adding an external 4TB drive. (enclosure suggestions appreciated.) After the warranty period is over, I'd like to replace the internal drive. I'd rather not have to copy off all the shows and was wondering if I could fill the 500GB internal, so that all the shows record on the 4TB only. Later when I replace the internal drive, with either a 3TB internal or larger external, would the external drive, and it's shows, still be recognized?...

Filling a 500GB Bolt to force use of External Drive?

Filling a 500GB Bolt to force use of External Drive?