***   How to Turn a Raspberry Pi Into a VPN-Secured Travel Router 
https://www.makeuseof.com/tag/raspberry-pi-vpn-travel-router/
Instead of a standard Linux distribution, you’ll need to install OpenWRT 
onto your SD card to turn it into a fully fledged router. You can use 
another Linux distro if you prefer, but OpenWRT provides a handy web 
interface for configuration when you’re away from home.