You can spend at least a couple of weeks in the DC area and not see it all! It really depends on what your interests are. The best thing is, from Cherry Hill you will not have to use your vehicle at all. They have a shuttle to the metro, which will get you everywhere. I would not relocate to go to Alexandria, just take the metro! Old town Alexandria is definitely worth the trip, but start early. It takes a while to get there either by car or metro. We took a water taxi back up to Georgetown after Alexandria, had dinner there and continued our site seeing. Don't misses are anything on the mall. Don't forget the Holocost museum, the national zoo, Fords theater, crime and punishment museum and the spy museum. Have fun!