This time, I am going to play it safe (or safer, anyhow) and set one of the drives as a hot spare.
Initializing the array was surprisingly quick considering its size. It only took around 90 minutes or so.
Drive E: Two trillion, one hundred and seventy seven billion, nine hundred and eleven million, eight hundred and forty four thousand, eight hundred sixty four bytes free
Drive F: Two trillion, one hundred and ninety eight billion, eight hundred and eighty five million, six hundred and thirty eight thousand, one hundred forty four bytes free
Hopefully, this should last a little longer than two years. If not, I'm still prepared.