For Halloween, a ukulele is no substitute for a broom.
I recently flew with my Kamaka HF-3 to Hawaii from California and back. I didn't use a humidifier (I have one of those Oasis things that you fill with water and suspend from the strings) because I noticed that the change in cabin pressure causes my contact lens solution bottle to leak and I didn't want any humidifier leakage. I think my uke was fine, and I tended to keep the air conditioning off in my hotel rooms.
As an aside, the Delta agent in Honolulu who checked my luggage for my flight home asked me about my ukulele. She said she'd never played one and was thinking of starting, but she didn't believe me when I said it was relatively easy to learn the basics. At her request, I took out my uke (there was no line at the time, as I was uncharacteristically early for my flight) and played "Happy Birthday" and the chords for one of the Hawaiian songs my class had played at the Maui Ukulele Festival, and then I handed the ukulele to her and showed her how to strum while playing a C-F-G7 chord progression. I left when people started showing up to check in, but while I was in the security checkpoint line, she ran up to me to thank me for playing for her and for letting her play.