Can I stay overnight at Chaoyang Station in Beijing?

You can spend the night at Beijing Railway Station, but I personally suggest you go to McDonald's opposite Beijing Railway Station, which is crowded and complicated, but safer than the railway station and warmer inside. Beijing has cooled down recently, and it's very cold outside. If you are tired in McDonald's, you can buy something to eat and drink. Even if you don't buy anything, you can stay there for one night. The bathroom is convenient.