Is it safe to manually move an iPhone backup?

My wife is badly out of disk space on her Windows laptop, and about half of this is iPhone backups made through iTunes. I want to move the folders with the backups to an external drive to free up space.

However, is this safe? iTunes manages these backups in a completely opaque fashion, and I don't know if moving them manually and bringing them back later is going to put something out of sync and prevent it from recognizing the backup.

You can understand my confusion: The backup folders are named by UUIDs and have a collection of opaque files. The number of folders (6) doesn't match the number of backups iTunes reports are available (3). I don't know if one folder represents one backup, or two backups, or half of a backup. I don't know if the folders are self-contained, or have metadata elsewhere that might get out of sync. I don't know if iTunes is going to tolerate it if things do get out of sync, or just throw up its hands and refuse to work with anything.

If anyone has some insight, a little bit of info about the nature of these backup folders would give me a lot more confidence with what I'm doing here. Thanks!