On Windows XP, I have tried connecting from the road to my home MythTV box via SSH using:
ssh -l mythtv -i [key file path] [hostname] -L 6543:10.1.1.203:6543 -f -N
I use the IP address for the mythtv box because I have other frontends on the network there.
Attached is my config.xml and log file.
MythtvPlayer connects, reads channel and recording info (that takes a while). I select a recording, click play. It starts playing fine, but as soon as I try to jump to the middle, or otherwise skip forward, it hangs. The files are transcoded, if that matters. Bandwidth isn't an issue, as far as I know.
I thought I had trouble with the backend at first, but I think that was user error.