The line that comes to your home is part of your ISP's Wide Area Network (WAN), and has a "public IP address". The signal that is translated by the modem is still part of the WAN and maintains that public IP address.

With Winston, the public IP address coming into your modem won't change, but Winston sends a private IP address to your router, irrespective of whether the modem is in bridge or all-in-one mode. The local IP addresses assigned by the router to the devices on the LAN don't change. If the router is in bridge mode, then Winston assigns a private IP to the devices.