@Embalmer12 you can restore the message threads, but it's all or nothing. See
http://www.idownloadblog.com/2014/03/06/how-to-back-up-restore-sms-messages/
I've done this on iOS 10 and it works perfectly.
To save space, you could TRY not including the Attachments folder, which is likely taking up most of the 30GB.
I recommend making a duplicate of the backup before mucking around at all.