I've actually applied to the PhD in Higher Education and was curious about others' experiences. I've never heard about their Instructional Design & Technology program, but I encourage you to reach out to faculty members! The Higher Ed program faculty were very responsive to my inquiries and I was able to meet with them in person to discuss the program. I've still kept in contact with them via e-mail as well, so I hope you have the same luck! Some faculty are more invested than others, but I'd continue to be optimistic!