Is it possible to somehow archive an old user's account so that it is still searchable and the e-mail accessible? Or is the only real way to get rid of an inactive account (but keep it intact for the future) to do a full backup and then restore just the account later if need be?

We have several license slots that are tied-up due to old user's accounts. They contain a lot of valuable info, though, so we don't want to lose access to their contents. Thanks in advance for any suggestions!