That would limit the available energy inputs though, miniscule solar radiation, miniscule tidal forces, so unless you've got active plate tectonics or radionuclide decay, it's all going to become ice, presumably?
There's some truth to that. Europa, Enceladus, and other places are more than frozen ice balls because they get tidal heating from orbiting a gas giant. Even so, there are probably vast amounts of rogue gas giants between the stars. The very largest of these objects are known as brown dwarfs.
