OK, so once again I declare that I am a mech engineer, not a programmer but you could run a small python or similar on your linux box, I guess a Pi.
From command line:
will return your Pi’s CPU temperature which can be used to operate a fan or even a stand alone fan/temp controller in the installation. Only issue with this is remoteness and no closed-loop I guess. I have some projects which use cURL to push messages via Pushbullet to mobile devices and Chrome for alarms and warnings, very handy for remote devices.
With regard to the packet forwarder it has a live log and a SSH terminal so very suitable for remote control/monitor of your gateway and seems very robust in the short while I am using it.