Battery Drain Overnight in Connected Standby

Question

Here is a battery report.

Here is a sleep study report.

I have a Surface Pro 3 with an LGC-LGC battery.  I have been having issues lately with connected standby, and I can't figure out what the problem is.  The reports say it all: I fully charge my Surface during the day, I pull it off at night and put it into my backpack, leave it in there all night, pull it out the next morning, and it is near dead.

According to the sleep study report, it seems like the the culprit is "USB xHCI Compliant Host Controller" at 94%.

Expanding that, it doesn't quite make sense.  Under that is the "USB Root Hub (3.0)", also at 94%.

However, the four entries under that are all green, taking 0-3% each.  I don't see how this adds up.

Hmm.....checking my Bluetooth adapter (which I unchecked the box "Allow the computer to turn off this device to save power"), the BIOS device name" is "\_SB.PCI0.XHC.RHUB.HS06".  This is probably what the problem is.  I'll re-enable that feature to see if that solves my problem.

It would suck if that's the problem.  I disabled that feature because Bluetooth devices stop responding after a couple seconds of not being used.  This means that clicking, mouse moving, and my Bluetooth gaming controller don't work for the first second of using them after this few seconds of power saving kicks in.  It's frustrating.  Disabling the feature completely fixed the mouse and controller startup delay, but it seems to be killing my battery.