neat idea but it requires a PC, this requires power and an outlet, which in a true disaster case is not possible.

Is there anything but for mobile? Or even a dedicated device.

Many people have generators for shorter term emergencies. Even in places with severe infrastructure damage they often have grid power, just unreliably and only for a few hours at a time.

Also there's solar. For the cost of a gaming PC you can get a solar and lfp battery setup that will power a laptop for a very long time.