It looks like we may be getting close:

---
Whenever the Vice President and a majority of either the principal
officers of the executive departments or of such other body as
Congress may by law provide, transmit to the President pro tempore of
the Senate and the Speaker of the House of Representatives their
written declaration that the President is unable to discharge the
powers and duties of his office, the Vice President shall immediately
assume the powers and duties of the office as Acting President.
---

Reports from Whitehouse insiders indicate that Trump's behavior is
growing increasingly eratic and unhinged. That's obviously a
dangerous situation. Let's keep our fingers crossed that we get
through to inaugaration without major incident.

https://www.axios.com/trump-white-house-conspiracy-theories-d95450a4-c7a3-4579-a568-0473b18529c9.html