Hi,
I am in a similar situation. I was diagnosed with carcinoma in situ. I am seeing an oncologist who did a cone biopsy. I did not get clear margins so he is now talking about ANOTHER cone. My attitude is similar to yours, if I have to be put under anesthesia AGAIN I just assume have him do a hysterectomy so I don't have to keep going through all this nonsense. I know (and so should you) that I will have to stay on top of this even though the uterus is gone because there is always the chance of dysplastic cells showig up in the vagina.
Are you seeing an oncologist? I would suggest you do with CINIII and also get a second opinion even if you are comfortable with your doctor.