Wow, Anchorage in January? Good luck!
When going into ANC, it's one of those airports where the sooner you book, the better. While most airlines run seasonally, in January virtually all of the metal going there is Alaska Airlines, who fly slightly modified 737 aircraft designed for severe weather (they service Fairbanks, remember). They even had gravel strip kits to land their 737-200's on unpaved runways until fairly recently, and even use a differently formulated fuel to service certain locations so that it will flow to the engines at -40F. Because of the limited winter supply, and the way the AS prices things, prices only tend to climb over time.