[iicc]

There's the Hurricane Electric IPv6 Tunnel Broker:

https://tunnelbroker.net/

>Our free tunnel broker service enables you to reach the IPv6 Internet by tunneling over existing IPv4 connections from your IPv6 enabled host or router to one of our IPv6 routers.

(It's still obviously less direct, and inferior to your ISP supplying native IPv6, but it may improve your situation.)

[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.