Yes, Hongkong is much warmer than most parts of China. It's still warm even at its lowest temperature.
We are still wearing T-shirt and shorts today, while most places in Mainland, people are wearing down jacket and wool overcoat.
Jilin, Heilongjiang， and Liaoning, these are three provinces in the northeast of China. Every house has the steam turn on, so only the outdoor places are cold.
As you said, CG is becoming popular lately just because Someone is trying to show off the CG badge to People live in Asian.