Wi-Fi Calling while in Airplane mode would not be subject to Stingray interception, and would protect IMEI data from airborne bulk capture.
Authorities can still set up open SSIDs to capture limited information about phones, but the "fly an airplane over" capture model doesn't work well with Wi-Fi.
You may be underestimating people's lack of care about what open access point people connect to. The traffic itself may be encrypted, but DNS queries, phone hardware addresses, and background traffic might not be.
I’m not trying to offer a comprehensive solution for avoiding government monitoring. I’m just offering a solution for avoiding cellular Stingrays while retaining cellular service.
For a more comprehensive solution, you would need to at minimum not carry any electronic devices (signal detection), wear a mask and IR-blocking glasses (face detection), and wear shoe inserts (gait detection) — and even then, they can still seize you and overcome those obstacles at will.
The context of this article is "Cops tracking your phone", of which the parent comment does not prevent in any meaningful fashion. The rest of the remedies presented here are also mostly unrelated to phone tracking.
Your summary of the context is broader than that of the article. The context of the article is "cops interacting with your cellular radio" in order to capture IMSIs and perform other interactions, using Stingrays and Dirtboxes.
Not carrying devices with radios is sufficient to prevent you from being tracked by them. I concede that if you carry a radio-less device and hardwire it to a network, then as in Battlestar Galactica, you have now removed some of the safety that the absence of a radio provided.
Authorities can still set up open SSIDs to capture limited information about phones, but the "fly an airplane over" capture model doesn't work well with Wi-Fi.