There are ways to try to stay hidden, like having one stationary and VPN to it from the second one; using a burner second/third/fourth/...-hand phone for the second, etc.
> In order to connect to the VPN, you must connect to the cell towers, which reveals your location.
It reveals the location of an anonymous SIM with no readable traffic, connecting to an unknown (if you use Tor) and also stationary and anonymous device, which might be planted in any random school, library, workplace...
> And no matter how many burner phones you use, as soon as you visit your home address, your identity is compromised.
Of course - don't do that with the phone on :) that's the basics, isn't it?