How about a slight change to the UK’s NOs:
5 IPCs if the UK controls the following territories: Scotland, United Kingdom (London), Gibraltar, Egypt, and Trans-Jordan. (Awarded to UK Europe Economy for maintaining Home Defence and controlling access to and from the Mediterranean).
5 IPCs if the UK controls the following territories: West India, India (Calcutta), Kwangtung, and Malaya. (Awarded to UK Pacific Economy for keeping the UK’s Asian centres of power intact).
Not quite as unreachable as controlling all original territories, but still rigorous, especially for the UK Pacific.