Any particular reason why you're picking a holiday time to travel?

Personally I'd go in mid-January to FAI ... yeah, it's cold, but so what? That's part of the experience!! Given the length of sunlight at that time of the year, you could just drive up to Chena Hot Springs and spend some time soaking in the pool (or hot tub), watching the aurora.

It was -40 when I was there in a late January ... warmed up to -25 while I was there but that didn't stop us from going out on my son's traplines, going up to the hot springs, and exploring other things in the area.