Good points, all. I should clarify: my reasons for choosing Hells Canyon are it's relatively close to where I live and I'm pretty familiar with the terrain, plus weather in the canyon bottom should be mild for the season, at least compared to upper elevations.
Andy: Good thought with the whistle, and good to hear the DriDucks have worked for you. The matches are backup for the mini-Bic--could just go with a second mini-Bic.
I'm comfortable and experienced with my stove system, so prob. need to stick with it for this trip, but have been thinking of trying Esbit at some point. This will be a shake-down for the Trail Gloves (has to happen sometime) but if I stick to the river trail plus side trips, it's pretty easy to dial back the miles if soreness becomes too big an issue. Again, Inov8 295s worked fine for me all last year, so I hope it won't be too big a change.
"Stakes are a luxury item..." Not sure I want to trust my tarp to the sticks available (it's an arid climate with few trees of any size near the river). The stakes I'm taking are bare minimum for my shelter, so will use rocks if I need a more secure pitch.
Dan: This is a similar sleep system to the one I used last April in the canyon, with an overnight low ~33-34F. I sleep pretty warm--I wouldn't say I was toasty, but never felt too cold. Differences are: the MB down inner has replaced a mid weight fleece, and I was using a 3/4 Prolite (2.2R) instead of CCF. The CCF I have is pretty dense--like Ridgerest foam rather than the plastic-y stuff--if anything I expect a little higher R value than the Prolite. Less comfort though. Still, a backyard test may be in order. FWIW, I measure single layer loft of my quilt at ~2"
Again, thanks for the insight. I'll post a trip report.