Without any kind of add-on, it suffice you shut off everything (make the cockpit cold and dark yourself) then save the flight as your default one.
Opening FS next, you'll find your cockpit cold and dark again.
That puts you at the location, and the aircraft, etc, where you were when you saved the flight.
I think the idea of the "Cold and Dark Cockpit" file was to start you off on the Main Flight Sim Menu when firing up the Sim...Cold and Dark, and "Create a flight" from the beginning.
Paul...

...!
If I can remember that far back, we were at Meigs Airfield, cold and dark, when we first fired up the Sim, and that became the default, before we started saving our flights.