I do seem to remember that when the Canadian ATC were on strike (probably 15-20 years ago) an Aer Lingus 747 going to JFK headed east out of Dublin, across WAL then to Ottringham. If memory serves me correctly it then headed up to Norway across the very north of Greenland and down to JFK by way of Alert, Resolute, Churchill and Thunder Bay. Certainly the long way round. (The southerly tracks via the Azores being fully booked from other departure points)