Originally Posted by
MrMB
Semi-related, but maybe of use to OP, having flown LHR>SFO earlier this week myself. Wi-Fi was reliable throughout the flight, besides disappearing completely for a ~3hr30min stretch between the western edge of Greenland & roughly when we overflew Edmonton.
That's entirely normal. If your route over Greenland is nearer the Nuuk end then you may keep a signal, but if you go any further north the service will stop until you get further south again.