So write a program that emulates 'regular HTTPS' traffic patterns. On the technical side of things, I'm pretty sure the VPNs have the upper hand in this game of cat and mouse.
As in, it is not only a passive observer periodically resetting connections, it will also make its own to test the waters
- In-Depth Analysis of the Great Firewall of China. Has other good sources at the bottom: http://www.cs.tufts.edu/comp/116/archive/fall2016/ctang.pdf
- How China is Blocking Tor: https://arxiv.org/abs/1204.0447
- Summary of "How China is Blocking Tor" from MIT Review: https://www.technologyreview.com/s/427413/how-china-blocks-t...
No DPI needed.
Until this is circumvented there is no real solution.