Is there a way to see current CPU frequency in macOS from terminal (not Intel power gadget)
Since your comment mentions that you're really just focused on enabling Terminal (or more accurately not desktop)...

I think that the Intel Power Gadget will help you get your info from Terminal. From Intel:


  Intel® Power Gadget also provides a C/C++ Application Programming Interface (API) for accessing this power and frequency data in your program; the API is supported on Windows and Mac OS X. For more information on the API's, see:


And on that same page, also a link to Using the Intel Power Gadget API on Mac OS X

Sorry this isn't a link to an out of the box solution; I spent a few minutes with google to see if I could find someone who already did this without luck.