Regarding accommodation stay on Hong Kong Island or mainland.

1. Well, November is a good time to tour around HK. There are many cloudy days. And the weather is cool and comfortable. Nice weather conditions will bring a happy mood for your sightseeing.
2. If just for sightseeing, 7-8 days are too much for HK. 3-4 three days is enough to cover the major ones. In the rest time, it is suggested to spend in Macao and Shenzhen, which is borderd to HK.