I turned off WiFi on the watch and the battery drain hasn't occurred ever since. Someone should try to see if they get the same results.
Didn't work for me. How long has it been since you've turned wi-fi off? If less than 3 or 4 days, then just wait. The drain will be back. It's obvious at this point that this is an O/S or driver issue on the watch. We need to wait for a software update from Google.