Dwarf Planet Ceres May Have Been Habitable – for Microbes – C0.5-2b Years Ago

The generic outer solar system body of a certain size has an internal ocean. Radioactive heat from the core can do it as can tidal heating as in the Io- Europa-Ganymede triangle. There's a difference between the case where the ocean is between two ice layers and the case where it is between an ice layer and a rock layer, the later is a better scenario for life because more diverse resources are available.

You certainly can run an ecology on chemical potentials

https://en.wikipedia.org/wiki/Hydrothermal_vent

and it's possible that terrestrial life started in such a place but not so clear you can get a tall enough trophic hierarchy

https://en.wikipedia.org/wiki/Food_web

to get higher forms of life and intelligence. Still I think about what happens if an ice dweller manages to drill their way up to the surface and see the stars.