Appointed a Companion of the Order of the Bath in the 1944 New Year Honours, McGrigor briefly commanded Home Fleet aircraft carriers at the start of the year. From 27 March 1944 he was Rear Admiral commanding 1st Cruiser Squadron (with HMS "Kent" and then as his flagship) participating in operations off the Norwegian coast and convoys to North Russia. He was mentioned in despatches for Operation Counterblast (the destruction of enemy shipping off the south-west coast of Norway in November 1944). From 8 April 1945 he also held the post of Second-in-Command Home Fleet, receiving promotion to vice admiral on 15 April 1945. The final air-raid of the war in Europe, Operation Judgement, took place in North Norway under McGrigor's command on 4 May 1945. On 7 June 1945 with the 1st Cruiser Squadron he conveyed King Haakon to Oslo on his return to Norway after five years in Britain, for which he was awarded the honour of Commander of the Norwegian Order of St. Olav. He was advanced to Knight Commander of the Order of the Bath in the 1945 Birthday Honours.