[ecksii]

That solution requires a routable, Non-RFC1918, IPv4 address somewhere to work. If I understand CG-NAT correctly, you don't get a routable address on your equipment.

[iicc]

You're right. HE is 6in4 and won't work.

There's a list of brokers at https://en.wikipedia.org/wiki/List_of_IPv6_tunnel_brokers

https://6project.org/ looks viable (OpenVPN) and cheap.