Time Capsule in bridge mode without ethernet
I'm probably missing something simple here.
I have a Time Capsule about 3 years old. I have a new router from my ISP that puts out a much stronger signal, so I want to use that router, but continue to use Time Capsule for wireless backups. From what I understand, Bridge Mode is what I want.
However, I also have a newer Macbook Pro with no ethernet port. So once I turn off the wireless setting in Airport Utility, the Time Capsule disappears, and the only way to bring it back is a factory reset, which takes me back to "create a new network" or "extend an existing network."
Without a wired connection, how can I tell TC just to connect to the router via ethernet (which it's doing), and not send out its own network at all?
MacBook Pro (Retina, 15-inch, Mid 2014), iOS 8.4.1