I'm a couple days away from finding out if we got a MF permit. If not, an Eastern Oregon river will probably be in my group's future for May. The John Day is on our radar, maybe the Grand Ronde. There wasn't much of a season last year, we'll see how this progresses. I really don't have much of a clue how low it can be run, but I don't think it would be fun below 2000. Desert rivers like that get a hell of an upstream draft, and if you don't have a 5000+ CFS pushing you down, the wind will push you up. The last time my group ran Clarno to Cottonwood it was 10,000. I missed the trip, but I heard the rapids were easy and miles passed easy.
If it's your first overnighter, that would probably be a good start in Oregon. I haven't gotten a chance at the Grande Ronde. I think it's a bit more challenging, but I think I'd like the camping there better. I don't think there is anything on either trip to really catch a reasonably capable boater off guard. Our group has been shrinking, and I'd like to add some peeps. I'll probably post my river plans on here soon...