CAR CAMPING THE HARD WAY
Sometimes I will just drive off into the woods in my car, stop and spend the night with what I have in it. Believe me, what you think is enough is often not enough. Tell your friends (the real ones) you are doing this so that they don't worry. Do it at a time when you have no commitments the next day because the first few times you will not feel like doing anything but eating, resting and getting a nice hot shower afterward. It is a wakeup call; planning is one thing, doing is another.
Do this not just on those nice clear summer nights when the moon is full and you can sleep in the car in comfort, do it at all times of year: winter, summer, fall and spring. You never know when you will have to do this. Restock and revise when you get home; I didn't and tried it again - oops! I stayed anyway for the lesson.
Water will be frozen in the winter and you must figure out how to thaw it. Running the motor is cheating in a way; the tougher you make it, the more realistic it is.
Don't get yourself in trouble by attempting to be a diehard. Know when to go home and warm up. Do not quit just because you are uncomfortable but think and adjust to the situation. This is a learning thing; don't go into hypothermia or get frostbite, learn and plan how to make it a little better. In the summer it is a great way to get away, in the fall and spring it can get cold and uncomfortable at night, but use this time to think and plan. Use the 'What If' to increase your skill.