Here's the situation I'm wondering if it will work on the road (example: traveling in a car far away from any known Wi-Fi AP).
Phone 1 has a SIM with data & voice. Phone 2 has nothing but Wi-Fi (no SIM).
Phone 1 can be set up as a personal hotspot. Phone 2 can use its Wi-Fi to connect to that personal hotspot.
Phone 1 has a carrier phone number provided by the carrier. Phone 2 has a voip-only phone number provided by a second-line app.
Is that a working method to get two phones with two phone numbers out of a single carrier's connection while on the road?