A couple of things to consider... (I lived in Spokane for 3 years) First of all, comparing Portland and Spokane is kind of oranges and apples. Spokane is a lot smaller town, although still a decent size city - there is a both good and bad to that. No traffic worries, much more "traditional" family values than Portland, etc. The local area is still beautiful (especially east into Coeur d' Alene) with everything you could want for outdoor recreation (Waterskiing in the summer to snow skiing in the winter) On the downside, Washington State is heavily biased to the part of the state west of the Cascades (Seattle, Tacoma, etc. where the big money is) so there isn't a lot of state funding support for roads, etc. Check on line resources to compare schools, but I think they are probably pretty decent in Spokane.
I hate to disagree with ATRCAPT, but there are definitely 4 distinct seasons in Spokane. Not sure where you are moving from, but the climate is radically different from East of the Rockies (i.e. Midwest, East Coast, etc.) and also very different from West of the Cascades (i.e. Seattle, Portland). It is a dry climate overall - you don't see a cloud in the summer time and it is beautiful. No it is not oppressively hot. The majority of homes in Spokane don't even have air conditioning. The average high in July and August is 82 and 83 degrees respectively - with very little humidity. (So at night the temp always drops into the 50s) If you are from the midwest/east coast you have no idea what this is like - no bugs, no afternoon thunderstorms, etc. There is always a week or so in the summer with temps in the 90s, but it is the exception. December - January average high temp is 33 with a low of 22 - yes that can be chilly and it will snow. Studded tires are legal in Washington State and you need them because they do a lousy job of plowing the snow. Here is the real kicker when thinking of commuting GEG-SEA in the winter - if you can't jumpseat on a flight, you may be in trouble because you can't guarantee you'll be able to drive the 5+ hours over to Seattle. They occasionally have to close Snoqualmie Pass (the mountain pass across the Cascades along I-90)for a few hours to a day at a time due to snow storms.
Spokane is a great town. It is a big city with all of the big city ammenities (Nordstrom's, etc. for shopping) but still has a small town feel. You probably need to visit to see if it is really what you are looking for. I've got a friend who has lived there for 11 years, works for a Major (not Alaska) and obviously commutes. He hasn't had that difficult off a time, but commuting is still commuting. You can't sit reserve in Spokane for a Seattle callout...