Little video of my test circuit in action. I still need to do a little testing to verify that the button is actually functioning once the circuit is powered on, it appears a little flaky but that could easily be due to the fact I slapped the code together in roughly 5 minutes.

The circuit powers the ESP32 on which immediately pulls the button input pin high, grounding the P-FET via an NPN.

Link to PeerTube video for those (like me, but they're no emmbedable) that prefer to avoid YT.