Tmobile access point (FAST 5688W) with google Wifi mesh – together

I’m trying to set up a network that combines the internet connection from a T-Mobile access point with the network hardware from Google WiFi pucks, and maintain the existing “myHome” network.

I would like to be able to unplug the T-Mobile access point and take it with me when traveling, but still keep the “myHome” network. Specifically, I’m looking for a solution that does not require me to change the configuration of the T-Mobile access point to put it back into broadcast mode. Any ideas?