What are your interests? Alaska is gorgeous in winter. If you ski there are many heli-skiing opportunities as well as Alyeska Ski Resort. There are also many companies that do snowmobile tours across frozen lakes and right up to the bases of glaciers. I don't know of any in particular but I imagine there's probably some dog-sledding in the area. If you're comfortable in the backcountry there is some amazing places for cross country skiing or snowshoeing.