Toshiba Satellite laptop
Core i3-4005U @1.7GHz x 4
Intel Haswell Mobile graphics
Fedora 25, running in Gnome3
Been having similar problems with freezing-when-unattended, since kernel 4.8.x-4.9.x.
(I additionally have total system unresponsiveness/freeze if I try to login using Wayland; I have to use the X11 login option to get to a useable desktop).
I'm wondering if there are similarities in the underlying problem with