After turning on the Sky+HD box one too many times to see 0% free I decided it was time to upgrade the Hard Disk Drive.
I followed this tutorial: http://www.skycopyplus.co.uk/forum/viewtopic.php?f=18&t=654 and had the new 1TB drive in, in no time.
Interestingly I found some articles referring to Copy+ http://www.skycopyplus.co.uk/ which can copy recordings from one drive to another (or at least used to be able to… but unfortunately no longer works- since a certain firmware version). Fingers crossed the makers will modify the code to work with newer firmware in the near future!
On a completely unrelated note I noticed my nan still has the same sky box she had 20+ years ago, and it’s an Amstrad! The Amstrad SRX200 in fact:
I honestly have no idea how this thing still works and what stations she actually receives through it!