[altoz]

First, yes, there are large farms of miners, but that's only some of the mining power. While these mining farms can be targeted and shut down, a significant amount of mining power is actually held in places that wouldn't be easy to locate. Those miners are going to keep mining as the owners have a strong economic incentive to do so, even if their mining pool in China gets shut down. They could, for example, just connect to a pool outside of China.

Also, what would happen to all the mining equipment should a mining farm get shut down? If the shut down is permanent, you can bet the people that own those machines would try to sell those miners as quickly as possible to people outside the country that can run them.

The economic incentives of bitcoin are such that there will be significant resistance to any government attempts at shutting down.