There is still airport bus at that time when you arrive at Hangzhou Airport. You can get round hangzhou first and then take bus at Hangzhou North or East Bus Station to Suzhou, a bit over 2 hours. Suzhou South Bus Station has buese to Tongli, 0.5-1 hour. Take bullet train from Suzhou to Shanghai, only half a hour and then take bullet train from Shanghai to Hangzhou, about 1.5 hours.