End of February and you can drive 2 hours from Fairbanks to Denali for their annual winter carnival in conjunction with the town of Healy.
And end of Feb/beg of March is the time for the Ice Art Championships in Fairbanks, definitely worth a trip both in daylight and at night.
And the Iditarod start is in early March.
So that new timeframe is excellent. I was in AK last March. Spent most of my time in Fairbanks but also went to the Iditarod restart in Willow and did a sleddog excursion for the day in Healy with Earthsong Lodge, which was excellent.
John