Make sure you spoof your firewall MAC before plugging it in to your ISP's modem the first time if you don't want them to recognize it every time you move.

How so? Port forwarding is a feat of the router, not the modem, so why not enable bridge-mode on your ISP all-in-one modem and pick up one of these WiFi routers for home and travel, and just plug it into your network switch.

NOTE: I'm not a fan of more powerful WiFi. I run line-in to most devices and would prefer my signal not reach the road since ofc neighborhood network scanning is a thing.