Luckily for me, Southwest flies out of RDU. So that's my go to airline for ski trips. The fact that SW allows 2 free bags, which can be a ski bag and another bag makes a difference. I have the luxury of being retired. I usually plan out ski trips in Sept or Oct. SW usually has a fare sale for Jan-Feb in Oct that includes SLC. Only last a few days so have to be quick.
May be unlikely for fares to change this winter. Since last season was bad and things are shaping up well, the airlines are undoubtedly aware of pent up demand. But I'm just guessing.
I used Delta to get to Bozeman for a Big Sky trip last Feb. A friend found a cheaper fare from SC that use Frontier. I've added Big Sky to my favorites list. Especially after figuring out that driving from SLC is a possibility when I feel like doing an extended trip for both places. The bonus is that Grand Targhee is on the way. Another place known to have good powder and few people.