Go do a search for "vampire drain" in the forum. You'll see numerous threads regarding this topic. At the end of the day, nobody has a clear answer of why the car drains on certain days and not others. Having said that on my good days, I get 1-2 miles drain and others I get 6-7 miles on an overnight drain. The latest software dropped that drain down from 10-15 miles in a 24 cycle to 6-8 miles. I think we've exhausted all the plausible scenarios (weather, software, and sleep cycles). Have not been able to isolate out the culprit
The two remaining explanations exist at this time:
1) I read somewhere that Tesla engineering says this drain is typical for newer batteries and will stabilize over time (not sure I buy it)
2) Tesla is doing a ton of data collection and hence not allowing the car to sleep (not just AP)
With both these explanations, we kinda have to trust that Tesla knows what it is doing and that the drain will stabilize as it has with the S/X. I kinda have stopped worrying about it since there isn't much we can do or hope for