Do you have any of the following apps installed... FaceBook, Spotify, Instagram, FaceBook Messenger, WeChat, Blackberry Messenger, Chat On or Weather Channel?
You can also boot into safe mode one night and see what the drainage is after that. That may tell you if it's a system thing going awry or something third-party.
Finally figured out the issue. This seems to be happening after the recent Android wear update. Either disconnecting the watch or disabling Bluetooth stopped draining. Will wait for update from gear app to fix this.