There are not six months of darkness in Alaska. The northernmost town of Barrow only gets 67 days of winter with no sun. Only places above the Arctic Circle get days with no sun during the winter, so a good portion of Alaska gets some sun during winter.
The further north a location is in Alaska, the more time of darkness there is during the winter. On the shortest day of winter, Juneau gets 6 hours and 22 minutes of sunlight. Anchorage gets about 5 hours and 28 minutes of sun and Fairbanks gets 3 hours and 42 minutes of sunlight on the winter solstice. During the summer, Barrow gets 80 days of uninterrupted sunlight.