I'm usually up at around 4:30 or 5 am on the weekends to do just this. I manage to get a good few hours of gaming in, with said cup of coffee, in peace and relative quiet. It's nice.
I too will try and sneak a game. However, my 5 year old ridiculous hearing and tends to hear me, even if I use headphones. I think he hears the click of the buttons or something.