"screen" isn't mentioned here I don't think except in the list of things to apt-get install if you're on a Raspberry Pi.  No big deal, it's small.  I've used it for years when I think of it.  When you ssh to a machine, log in, then type screen it starts with a blurb you can ignore by hitting enter.  If something interrupts your connection, like if it's over WiFi: reconnect to that machine, log in, type screen -r and it will resume your session.  cgminer can be running just fine the whole time and doing work.  I just did that, I have my old 2Pac plugged into a Zero, started over ssh from my laptop.  Laptop crashed, I rebooted and reconnected, the Zero's still mining away like nothing happened.  (blinky light was going, even  disconnected)  FYI the Zero (ZeroW with wifi) and 2Pac were running mostly fine on a 2.5 amp cell phone charger with an OTG cable between, little 4 inch one.

You start ssh by enabling in raspi-config normally.  Once that's on you can connect to it, that's what "running headless" is all about.  You don't need a monitor, you just connect by ssh from some other machine.  ssh username@machinename