At this point, your landlord should have turned your utilities back on. The purpose of this hearing is to prove to the judge that you need your TRO to last a longer period of time.
If your landlord has turned your utilities back on and there doesn't seem to be any more problems with your utilities being turned off again, then this hearing may not be all that important. You should go to the hearing, but explain to the judge that your utilities were turned back on.
However, if you are still having problems with your landlord and you think that you need a longer TRO against utility shut off, you need to prepare well for this hearing. At your hearing, you will be required to prove that your landlord has intentionally turned off your utilities. Bring any witnesses or evidence that will help you convince the court that you have a valid rental agreement with your landlord, and that you were denied access to your utility service.