I like what Shelby suggested. There are B&Ms that rent lockers, so why not ask if they'll store your humi for a year for a reasonable fee. As Shelby said, the possibility of loss, damage, or confiscation in transit is probably the greater risk.

A full year in a sealed cooler? Interesting. I have no idea if a sealed coolidor would hold RH for a year with just beads and no maintenance. My guess is that the sterilization would have to be impeccable before you sealed the box. Now I'm curious. Anyone out there tried this?