As soon as I went to work the home network dropped off the internet, wouldn’t you know it. It turns out that was the time the old lease ran out, and it wanted my router to ask for it again. As I’d configured it to static to deal with their lease issue, no such luck.
Fixing it when I got home taught me another lesson, it’s actually really important to clone the MAC address as well of the old router. With the original MAC address in place I couldn’t get a DHCP lease. With a clone of the FIOS router, all was good.