I had MQTT on and was connected to WiFi.
I’ve since turned both OFF and now I’m locked out of the device.
Do I need to do a reflash/reset?
Silly me. 
When you turned wifi off, Bluetooth should have come back on unless you intentionally turned it off when you turned on wifi.
If you did that you should still be able to reach the device through the usb port and the web interface, unless you also turned off the serial port.
Sorry, false alarm.
It’s my phone bluetooth that isn’t good enough to see the #1 node on the roof. My #3 node (ironically right next to my phone) can see the roof #1 via radio.