Can you advise me how to reach the Guangzhou Airport before 8.20am without massive traffic?

Well, according to your departure time, you are advised to take a high-speed train from Zhongshan to GZ South Railway Station one day in advance. Then stay at a hotel nearby the railway station and get to the airport in the next early morning by taking cab. The cab fare is CNY 170-180. It takes around 45 mins on the way.

You can stay at this hotel near the railway station...Xinghe Xiangjiang Hotel. Clean 3.5 star hotel. only 1 min walk from airport bus. You can also take the subway to the airport but I do not recommend it. Lots of taxis for 120rmb to the airport. Bus is 18-20 rmb i think and 7 rmb for metro. It is better to stay overnight in GZ since your flight is early and avoid rush hour traffic.