Sillyhotdogguy,
Were you successful in removing the rear seats from your C-Max? I am in the same place you were when you posted on June 30... long road trip in the works, need extra storage and would like to sleep in the car.
I have the Energi model but have never tried to run a/c all night. The Energi has a feature that allows for saving the charged battery for later. You have to remember to engage this feature every time the car is started.