There really isn't a way to do this using your coax and your dish devices.
Wireless hdmi devices may work, but I'm not sure any of these can distribute to multiple tv's.
MoCa adapters can run data on your coax, but a device is needed at each tv to display the feed.
You can run actual hdmi cables or cat-6 based hdmi extenders to each location and use a hdmi spliter or matrix switch to distribute the signal.