You have gone way outside it whilst on base
Negative, one must remain within two miles during the circling maneuver.
You will note that I mentioned...no more than two miles on final...normally it is about 1.8 miles, with the possibility of landing flaps selected whilst in base, and the descent begun at that point.
Is this allowed?
Yes.
The FAA requires very accurate flying, and it certainly can be done.
Is TERPs limiting?
Yup, sure is.