Yeah, sometimes Google Play Services (which, IMHO should be broken down into all its tiny pieces to figure out when something goes wrong) can act a little crazy.
If this becomes a constant issue, though, what usually clears it is to uninstall updates to it, reboot, and let it re-install itself. I know this helped me go from 10 hours per charge on my old Note 2 to nearly all day long. And yeah, locations services are the most power-hungry features. Also, even with WiFi on, unless your phone is actually sending/receiving anything, it shouldn't be that much of a drain overnight. Mine, when I forget to charge it at nighttime, usually drains about 5 or 6% with WiFi on.