Q: Might you only insulate the ceiling of the utility side of the bsmt if half of the bsmt is conditioned space (family room)?

A: Yes, this is a good idea – insulate the basement ceiling where you don’t mind the basement getting a few degrees colder. If the basemetn space is living space then it is better to not insulate the basement but instead insulate the walls and add a thick carpet with a thick underlay pad.