I have a very early morning flight out of CDG (i.e. have to leave my apartment in the 15th around 4 or 4:30am before the metro/RER start running). I am staying in an apartment not hotel so I cannot have them help me. What is the best way to get to CDG at that early hour? ARe there shuttles? If so, how reliable? Should I call a cab? If so, what cab companies are best? Thank you!