My suggestion is pretty much the same. Shelter and fire most important. Hopefully it won't rain that night so somewhere out of the wind if you can find it. Or build a small shelter toprotect you from the wind. Some handy items you should always have is a lighter (of something to start a fire with), some fire starter (a 35mm film container with vaseline soaked cotton balls is light and easy to carry) and some parachute cord which is also light. Also, some quick energy snacks (granola bars, etc.) and water. These three items don't take up much space and can save you form an uncomfortable night. I would advise you that if you believe there may be a chance that you are going to be staying the night that you let your firends know. But be sure to make it back by the following evening before they start looking for you.