Can I copy and paste iDevice backups to an external drive? I need disk space and thus would like to move an iDevice backup to an external drive temporarily. The online guides which show how to do this go into too much detail, showing you how to make symlinks in order to keep the backup on the external drive. Since I want to move the backup temporarily, I don't need all of this.

Can I copy and paste the backup to the external drive, delete the original backup, and then copy and paste the backup back when I have plenty of space?
Yes, you can do this. 

However, if you have a Time Machine backup1 you should already have these backups included, so you could potentially negate the need to copy the backup twice.

Either way, I'd do a fresh backup of your iDevice before proceeding.

1 You should definitely have some sort of backup regime in place, even if it isn't via Time Machine.