Maybe, but if anything bad happens to originate from that number, the port history is still visible and now they have a suspect.

• any carrier within range can still potentially track you, maybe not with airplane mode but Snowden says don’t trust that

• GPS still “works” without any signal, service or net access

• AGPS mandate forces 911 calls to reveal your location

For max privacy without going completely analog you’d want a device with NO cellular radio at all