So I have a friend with Microsoft was able to look around a bit and said the sleep drain issue appears to be manifesting with certain load orders of patches. Of the others he knew about one restored to original and then just loaded the latest update and
has not seen a recurrence yet so far.
So I did a reset, which took me back to 1511 (not what came on the SP4). After letting updates occur by Windows Update, consumption seems about 3 percent per hour, not good.
I wanted to do a full reset using USB media, but I'm concerned because I do not have a product key, and the media creation tool says you need one. The tool was recently reverted back to pre-1511. There is now a statement that “These downloads cannot be
used to update Windows 10 PCs to the November update (Version 1511).” which is apparently a change to the download page. If that means you won't be able to then go to 1511, I’m guessing this is because of the issues with the Surface Pro 4 and the Surface
Book with 1511 and subsequent updates. It also may mean that you would then have to do a subsequent update to 1511. It can be taken either way...sigh...
Go to Surface.com and download the image. You copy it to a USB drive (fat32 formatted), and turn off the surface and press the volume down and power, release the power. When you see the Surface logo you let go of the volume down. No need to use the tool.
No key needed. It's stored in its firmware. :)
I'm testing right now battery drain. I'm going to watch a movie and have dinner soon, and I'll leave my SP4 unplugged and in standby. I'm keeping my fingers crossed.