He left his wife after the wife and moved to Canada where he worked as a mechanic at Rolls Royce in Halifax, Canada before meeting his second wife, Minnie LaRue who was from the Isle of Guernsey. The two married and returned to Guernsey. During World War II the islands were occupied by Nazi troops. The occupying German forces deported over 1,000 Guernsey residents, including Mitchell, to camps in southern Germany, notably to the "Lager Lindele" (Lindele Camp) near Biberach an der Riß and to Laufen. He returned after the war. John Mitchell died on 2 January 1964 on the Isle of Guernsey of coronary thrombosis and arteriosclerosis.