Man of Honour
Have you tried this, does it work?
And how to return to original if we don't like?
Not tried it with Nova Launcher and it does return to original size.
Reported to also work with other apps (see link comments).
Not tried this method:
http://forum.xda-developers.com/galaxy-s7/how-to/guide-how-to-change-dpi-root-t3335596
I have tried this:
https://play.google.com/store/apps/details?id=com.evozi.displayscaling
and it works fine and reverts back if you want to.