Music would be good along with important documents like ID, insurance, apartment leases, etc. Maybe some portable games to kill time. I use a password manager, so a copy of that database goes on there.
For my situation, an ICE USB drive wouldn't really work. I'll almost certainly have a phone with me, but no guarantee of a device to read the USB drive. I have a cloud storage/file sync service that I use. It has important documents along with most of my daily-use type files. This is the most available backup I have, but I also have a USB with the same stuff just in case something happens.
The cloud storage is Nextcloud running on a Virtual Private Server (AWS EC2). AWS is complicated but extremely reliable. As long as I don't fuck up the config or leak the server's access key, that server is live no matter what happens to my computer, USB, home, etc.