For those missing the public IP address that the old 3g devices used and wanting a way to access their network remotely I recommend gbridge. http://gbridge.com . It's a free program that used the Google VPN server to enable a VPN connection between two or more computers. It supports it's own secure share and can be setup to enable RDC, VNC, windows folder sharing and many other task. I have used it for years and I just tested it with a 4g connection and accessed my network via a public WIFI with no problems. You do have to have a Google account and the program is not affiliated with Google.
You should be able to connect natively with VPN now even with the default NATed 10.x.x.x address. Verizon engineers made a change to their eHRPD tunnel end-point gateway to allow the VPN packets through.