By my count, Idaho Democrats have not (yet - there's still primary opportunity to fill spots) filed candidates for all but 26 out of the 105 legislative seats.
That's a goodly number, but it's actually a good deal better than in the last couple of cycles - not much more than half as many free rides for Republicans as was the case two years ago, or two years before that. More seats have more Democrats running in them than usual. The Idaho Democrats did much better with candidate recruitment than usual.
Idaho candidate filing wrapped today, and there seems to be more candidates filing for the legislature than usual - in both parties. Not sure what that portends.
But take this as a reminder: In Oregon two years ago, the minority House Republicans filed for more seats than they historically had done, and wound up winning more seats than anyone had originally expected. Worth bearing in mind.