Trying to decide between heading to SLC to crash at a friend's place, or spend about the same to go to Spokane and hit a few of the above places. We're probably looking at the first week in March, if that factors in.

Basically, airfare to SLC is running around $400 for that time, Spokane is under $250. With the extra $300, we can get rooms and a rental and see some new places, plus it looks like they're having a pretty "OK" year compared to SLC and CO.

Of course, if they're not worth the trip, they're not worth the trip. Anyone here spent any time at any of those three? Anything worth making a trek cross-country for a few days?

Haven't done those, but I have done Red Mountain and Whitewater. They're both among the greatest places. Both are driveable in 2-4 hrs. From Spokane.
Bring your passport.

Actually, I was just going to edit to ask about those two. I didn't realize they were so close to Spokane.

Is March considered "late season" (meaning spring conditions, I guess) up that way? I'm hoping not...

Early March OK, late March could be great but not assured. Those places have low base elevations. Also several interior BC areas have closing dates set by when the bears wake up.

My wife and I just went to Schweitzer MLK weekend for the first time. We had the same dilemma that you did - we were planning to go to SLC, but there was less snow and tix were more $$$, although it would have been an easier trip. We loved it, connected in Den to Spokane, drove ~ 1.5 hr to Schweitzer. We stuck to the intermediate groomers, there are a lot of those. It is a nice big resort with very few skiers, it's about 2900 acres, with probably fewer skiers than you would see at Liberty/Whitetail on a weekend. It's got some great glades, and it didn't snow significantly the 4 days we were there, but there was plenty of snow, everywhere. The pacific northwest hasn't been hurting for snow like the rest of the country. I would guess you would have 'spring conditions' in late march, but there should still be a good amount of snow. They average 300"/ yr, and are doing well so far this year. There is a great Schweitzer trip report on epic ski from the end of Dec. even MLK weekend the most we waited was 10-15 chairs to get on, and that was rare. During the weekdays we were there we skied onto every lift.

Looks like we're headed north. Flight to Spokane is booked, and we've got a room in Rossland to ski Red for a few days. I'm a little worried that we'll be in over our heads, but I couldn't resist the chance to do something different (and log my first international turns).

Hopefully conditions will cooperate enough to give us soft snow. Given the reported steepness/gnar factor, I don't think we'll have a good time if things are icy.