Tesla appears to have made a change to when the car is willing to go to sleep with 8.1 (I'm on 17.14.35) that is of interest to people who monitor their car via a logging site like TeslaFi. Past behavior has been that the car would not go to sleep unless it has not been polled for 15-30 minutes, meaning that the car has a higher vampire loss because it never enters sleep mode. Because the higher vampire loss is an issue for some folks, some logging software/sites, like TeslaFi, implement special logic to suspend polling for a time, allowing the car to go to sleep at the cost of potentially missing some data.
With 17.14.35, I am finding that my car is willing to sleep when idle even while being actively polled. My specific experience is with TeslaFi, where my configuration permits continuous polling once every minute from 7 AM to 11 PM. On days where the car is idle, I am finding the car is entering the sleep even during the daytime hours, when previously it would not. The car may go online for brief periods, but then it happily goes back to sleep. I call this "napping." On days where I use the car, I have seen this napping up until I drive the car. Once I have driven the car, it won't nap any more until the next day, after a night time sleep.
Note that for the car to sleep, it appears that the options for energy savings must be selected and continuously connected must be unselected. This is my configuration.