USB-A powered device to just run 2-3 scripts, plugged to router

So here's the deal: I need to monitor the status of a home internet connection remotely (for a family member), and would like to have 2-3 shell scripts running from time to time to update a dynamic DNS name.

Even a Raspberry Zero seems to much at this point. Is there any sort of super mini device that can run plugged in the USB-A port of a modem and that would just run scripts I put in it? Bonus if I can SSH into.

I think I'm dreaming and Google didn't help, but maybe I missed something...

Thanks