Plug in the Tesla Model Y and leave Sentry Mode on or set Camp mode with HVAC fan only on Low. The Tesla Model Y will remain powered on, not enter sleep mode. In this way the Tesla Model Y's 12V systems are powered by the on-board power conversion system DC-to-DC power inverter, not the 12V battery.
Good call. I was going to shut off sentry thinking it might have some drain on the 12v even though sentry is powered by the main battery.