Monday January the 4th I'm arriving at 9 PM at Pudong, and want to go to Hangzhou that same night.

According to your timing, the only way with public transportation is to take a train. The last train leaves from the South Station at 23:30. After landing, you should hurry up to check out and take a taxi to the South Station. Maybe you can still catch the train. By it, you may reach HZ around 03:10 the next day. You may also consider hiring a taxi or private car from PVG. It shall cost CNY800-1,000.