They don’t just block based on IP, they also do deep packet inspection so if you use say, the OpenVPN protocol without changes, it can be blocked even on a private server.
On my browser (Firefox 59.0.1), the page displays "undefined" in a couple of places, then, after a couple of seconds, it displays what appears to be the complete, correct page.
http://startuplivingchina.com/how-to-outline-vpn-setup-china...
I imagine a multitude of small privately run VPNs will be much harder for the Chinese government to shutdown versus centralized VPN providers.