Boot hangs at flickering screen when starting GDM when using 352.x or 355 driver with GTX 980

I’ve been fighting a weird issue here. When I install the nvidia proprietary driver, the driver builds (supposedly) successfully but when I reboot into the GUI, the boot will hang at starting GDM and the screen will just flicker, forever staying at the dmesg output of starting gdm until I reset the box.

This happens with F21, F22 and F23 across any of the default installed kernels, or the latest 4.2.1-300 kernel, and when using either the 351.21, .30, .41 or 355.11 driver. To be clear: yes, I have tried each of those drivers against each of the four kernels and the result is the same.

However, I do not think this is a hardware error as the card performs perfectly when I boot to Windows 10 using the latest drivers. KF2, FFXIV and Star Citizen will each run without errors or artifacts even when running on a 5760x1080 resolution and the GPU at 100% load.

I am not sure where to go next, so any pointers would be appreciated.

Bug report log:

For reference, relevant hardware specs:
CPU: i7 6700k (not overclocked)
Motherboard: ASUS Maximus VIII HERO, BIOS version 0805