Oberleutnant Franz von Werra from Canada across the St Lawrence to (then) neutral USA.

Worth checking out "The One That Got Away" with Hardy Kruger as Von Werra, alot filmed at the actual escape locations.

More Info on Von Werra

I notice this article mentions "He was only the third German prisoner of war to make a successful escape from Canada. The first man had managed to return home via Japan and Russia, but the second had been handed straight back to the Canadians" Never heard about the first one...?