If we had an option to only charge the traction battery while the car was awake (usually this is because the 12V battery is being topped off) the awake overhead could be reduced. The 12V battery in my three year old Model 3 requires a top off about every 18 hours and the time to perform this function is 2 hours. I would assume a newer battery would not need to be topped off for 24 hours or longer? My charge rate at home is 21MPH so as long as my average daily miles driven is under around 39 miles per day (allowing for the phantom drain power used while the car is sleeping) no additional charging would be required. In this example, the power savings per month could approach 7+ KWH. That might not seem like much but over many years it adds up; likewise, if the current fleet of Tesla's saved even 4KWH per month it becomes more significant. On a side note, it would be nice to have a selectable option in the Tesla phone app that sends a message when the car wakes up and and another message right before entering sleep state.