I’m reasonably sure that you fellas are out of luck, to my best knowledge there is no official way to make this work without X.
This said, there are unsupported ways of doing this, like customizing BIOS for your cards and enforcing fan target / fan curve / constant clocks etc.
http://cryptomining-blog.com/1014-how-to-increase-the-geforce-gtx-750-ti-power-target-limit/
Basically, biostweaker is a tool for user friendly bios editing, nvflash is a cracked nvidia tool that allows you to flash non-signed vbios images. This is one time thing, once flashed it will just work they way you set it up.
Please note that you keplerbiostweaker is a .net app, but it works in wine with dotnet30 installed via winetricks (or if you have windows box lying around you can modify it there). Nvflash for linux does exist (just google for it).
Don’t believe that pascals in-hardware signature checks have been cracked (yet), so 1080 owners are probably out of luck.
PS: nvidia folks don’t support this and it might or might not void your warranty