[mnw21cam]

Most of these nation-state-run blocking attempts tend to block known VPNs but allow ssh through. So, my suggestion would be ppp over ssh. See https://tldp.org/HOWTO/pdf/ppp-ssh.pdf for more details. You'll need a Linux-ish server, and you'll need to fiddle with routing tables on both the server and the client to get the incoming VPN connections to be able to contact the wider internet. But it's probably the least likely to be blocked.

[justsomehnguy]

It's quite trivial to tell if this SSH connection is just a tty or serves as a passthrough for something else, just by usage patterns.