If you're finishing a Master's dissertation, your usercode will not be disabled until you have submitted your work and it has been assessed.
We cannot extend your access rights once you have officially completed all your courses as we need to free up the resources for new students.
If you're likely to be returning to what is essentially a continuation of the same course (E.g. Certificate to Diploma, HND to BSc) you shouldn't have to do anything and will continue to be able to use your usercode as long as your Faculty is aware that you are transferring to the new course.
If you're returning to a completely different course in a different Faculty (E.g. BSc to PGCE), you should be able to keep your existing homespace and existing external email address (E.g. firstname.lastname@example.org) as well as the contents of your current Google mailbox and address book.
Please bear in mind, though, that homespace is an area for "work in progress", not a permanent storage area. You are encouraged to back up your work to USB sticks, CD-ROMs, or internet-based storage regularly, especially if you are in what might be regarded as a "course finished" position at this time of year.