@GatorGuy , oh wow that's a significant amount. Do you have any background services enabled, such as smart charging, automatic behaviors, home screen widgets, Wear devices, etc.?
What's the average outside temperature where you're at? Are you plugged at all during the 24 hours? Is the car stationary or is it moved some times during the 24 hours?
What firmware is your Tesla running? Does it have the climate keeper feature that allows you to keep the HVAC running after getting out of the vehicle?
What battery size is your vehicle? On a 75D with max range ~250 miles, 15% would be ~37 miles over a 24 hour period which would roughly equate to running the HVAC for a day at room temperature-ish.
I may be way off on this so just a guess, but if you recently upgraded your Tesla firmware and gained the climate keeper feature you also received a hidden change in remote HVAC activation behavior. Previously when remotely starting the HVAC it would turn off automatically after 30 minutes, with the newer firmware this is no longer the case. It will run indefinitely until you start the car, turn it off remotely, or the car battery drops below 20%. I frequently turned the HVAC on for lunch and forgot about it for hours only to find significant drain by the time I did go out to the car.