Due to the unpredictability of getting across the border into Canada I scheduled my late January ski trip through WA, ID, MT, WY.
On your list I'll be hitting Schweitzer, Big Sky and Grand Targhee.
I've skied a lot at Schweitzer in January and had great luck with catching the storms. Missed the storm last year at Targhee but had an amazing time with hiking to get first tracks with some locals. Because of the distance between those two location and the fact I picked up an IKON pass, I'll be adding Big Sky as a stop. I'll hit a lessor known resort for weekend skiing with the plan to ski the bigger resorts during the week.
Here is a link to weather info I use for the area. In addition to his blog, I'll watch his youtube videos
The official blog of meteorologist Chris Tomer featuring interesting weather, expert-level forecasting, guest blogs, and new perspectives.
christomer.com
If you need someone to ski some trees with on your visit in January let me know.