I might go with XFCE being small as it is, or maybe some other small not very looksy Gnome distro. Like mandriva.
Mandriva is kinda down the drain right now, you might wanna go to Mageia fork (which is basically the whole Mandriva team under a different name).
https://www.mageia.org/en/downloads/ There are available both Gnome or KDE LiveCDs 670 MB in size and also a minimal (dualarch) LXDE.
Those two LiveCD include some proprietary WIFI and video drivers making the installation a bit easier.