I, not only have a separate /home directory but, if the Hard Drive is large enough, will create things, like /bighome, /oldhome (just before installing a new Release), as well other variations, to handle the "Issue de jour".
Why? Because /home is where my "personal data" is stored, and I don't want anything to go wrong. (For example, I avoided an issue that showed up on this List with /oldhome, when jumping from Ubuntu to Debian, including going from Open Office to LibreOffice. Didn't someone lose Templates recently?)
Note: If I am short on disk space, I will, at least, "tar and feather" my filesystem, before the Upgrade. I have two One Terrabyte external Hard Drives for this purpose.
Good luck!
Kenneth Parker, Reformed Ubuntu user, now mainly on Debian.