Transferring to Newcastle Uni

Hello, I am planning to transfer from the University of Glasgow into year 2 at Newcastle University.

I have confirmed my acceptance to Newcastle but I still have one unfinished course at Glasgow to complete before I receive my grades.

I also chose to participate in the Study Abroad programme at Glasgow (I would have studied in Canada under the same uni had I not chosen to transfer).

Basically, I am unsure of when to inform Glasgow uni of my transfer. On one hand, I feel it would be better to inform them as early as possible so they can stop the arrangements for my Study Abroad. On the other hand, I want to wait to finish my course and receive my grades before telling them.

Any advice on this situation would be greatly appreciated