Don't live in Oregon, but relevant to this: there's a broader acceptable range of RH than what sometimes gets declared...with a few provisos.
If the instrument was built in an environment around 50% RH, you'll do OK between 40-70%. Around 40% go with a Herco or something. Around 70%, maybe your place could use a dehumidifier.
If you have a uke equivalent of a Taylor guitar...that range might not work out so well. The uke equivalent of a Martin (yeah, the S-O is thinner wood...so careful everywhere with handling) but I'm talking here the not so thinner wood offerings usually not handmade and not as touchy. Somewhat overbuilt as they say in modest priced solid wood offerings? Yeah, with loss in resonance but maybe better for more knocking around, less touchy, less fragile. Tonewoods and construction matter. Frankly I'd be more careful with a koa than a mahogany since when a koa gets dry...not as easily resuscitated, hydrated. Also, the rate of moisture loss for a wood instrument? Not rapid, not arguing for abuse, and yes the smaller uke has a shorter dry out time but it's not 3 days at a moderate room temp.
I still maintain that temperature is the dealbreaker and unless it's a uke case designed by NASA you can't expose the uke to prolonged temp extremes...and always with solid woods, let the case adjust before opening to changes in temp.
Hey Josh, you can always do what what I do: play only sopranos and mostly lams and not all solid woods, LOL. In short, cheap out. Ever heard a truly "lush" sounding soprano? Not me. I don't see a Martin 5K in my future...or even an entry-level Kamaka. Believe me, my wife also shares that vision.
