Of course, Hangzhou has daily flights to Hong Kong. There are 6 flights or so in the morning departing from Hangzhou to Hong Kong, so it is not difficult to book tickets. You will want to arrive at least 2-3 hours before the plane departs to be sure to clear security. If you stay in the downtown area of Hangzhou, a shuttle bus is a great way to make the commute. Be aware that if the flight departs at around 8:00 am, you will need to take a taxi.