The best route, especially if it snows is to take I90 east to the US 95 exit in Coeur d’Alene and go north from there to Sandpoint. These are the main arteries are are cleared first and continually.
TBH, here in CdA we’ve had very little snow since Christmas. Thanksgiving week to Christmas we got a boatload of snow and I was shoveling frequently. Then it turned to rain for the lower elevation or snow that has melted quickly. The Interstate and US 95 up to Sandpoint at this time are bare of ice and snow.
The mountains are supposed to have fresh snow this weekend with a shot of frigid air. We are just supposed to get a trace in CdA so I expect the roads will still be clear.
Hope you get in some great skiing!