exlegend, I have been told, by Muslims who live in countries like Greenland, since the hours between sun rise and sunset can, at times, be extreme in these countries due to their location, that Mecca time applies  for them. And this is how most Muslims handle the situation, to the best of my knowledge.

for example...in Sweden ithe sun sets between 8 and 9 in the evening. People break their fast at Mecca time. I know this because I am here at the moment.