If you are able to have a laptop or other computer at the remote station, then you may have success with setting up an OpenVPN server at home, and a client at the remote end, configured to maintain a permanent connection to the home server. As the traffic to build the VPN is Outbound from the mobile network, it’ll avoid the carrier natting issues.
This would give you a VPN tunnel you could route the Remote Rig traffic through. A bonus is that if the Internet ISPs block any of the ports Remote Rig uses, it won’t matter as the ISP will only see the Port used by the VPN and you can set that to anything which works, I often use 443.
If you used the PC for Digital Modes you could also use Remote Desktop to connect to the PC for digital operations.
Martin