Slight mistake with 24 hour daylight...
...Sitka is not that far north. Its 58dgs north, same as north Scotland, the Sun is 9dgs above the horizon in Winter.
I sometimes wonder why films make little mistakes like this? It would be far easier to:-
A)Not have 24hr daylight hinted at, or
B)Set it in a town far enough north for this effect?
Heck it wasn't even filmed in Sitka, it was filmed in Rockport, Massachusetts..