I have not set it up yet but plan to do so soon. I could imagine a requirement of owning a host name so that you can have a certificate, but I imagine an IP address would work just as well. You will need to open ports on your router according to the documentation; I haven't looked into reverse proxy options or anything to prevent the firewall changes being necessary.
But yeah, my understanding is it's totally doable for "free" (i.e. using your existing infrastructure).