Neat.
There are routes, remnants of Bluie and Crimson from delivering airplanes to WWII.
Greenland to Iceland and Iceland to the Faroe Islands are very long legs, must have had ferry tank.
(Unless there are islets with fuel along the way, even ones called ‘barge’.
I worked with old timer pilots who claimed to have flown Empire Flying Boats across the north Atlantic, landing beside barges if necessary.
My reading today suggests those were ‘connect the empire’ fights, few pax, not viable so only a few flights made.
The Faroe Islands being the closest runways to Iceland on Great
Circle routing.)