Hey Sarah, great question! The one time I did something similar, I wasn't particularly concerned about data for NGS work, and basically removed the EtOH but kept everything packed in moist, etoh-soaked materials, wrapped extensively in bags and such. If you have any contacts at museums/natural history collections, I'd reach out to them. Otherwise ping me off line and I'll try to connect you with someone that might have an answer.

Thanks, Michael! I got similar suggestions from others so there seems to be a consensus about pouring off the ethanol, and then shipping on dry ice if possible. I also learned that international shipping regulations will allow a certain maximum volume of ethanol per package if packaged properly with the right sticker, so I have some options.