How often do MIP 2nd offenders actually go to jail?

I do not have enough information to answer your question. Many different Judges in this State deal with these types of charges in different ways. If there are things that you are doing on your own to address any alcohol or substance issues that exist, that may help you get a better result. Are you in counseling? Are you in AA? Do you have a sponsor? Are you in school? Are you working? Do you have any mental or physical health issues? If you can afford a lawyer to help you, you should. A great lawyer may help you receive a great result.

The Judge in this case indeed has the authority to issue jail time for a second offense, but often times the Judge is more concerned with you taking the necessary steps to address your battles with alcohol and underage drinking. So the issue will be what steps have you taken while on the diversion program to seriously address the issues and conditions the Judge required of you. If you simply blew everything off, made no progress to complete the diversion program, and still picked up a new MIP offense, then you leave a wide door for the Judge to issue increased penalties other than diversion.

Pack your toothbrush. Apparently, you do not have any respect for the judge, because he or she let you slide the first time, with your promise to behave, and you went out and did exactly what you promised not to do. Obviously, you do not get it. So when any judge has some kid drinking like a fool while on probation, then a judge normally automatically will want to put you in jail to get your attention and compliance. And normally, they have heard all of the apologies and nonsense excuses a thousand times before. You are shaping up to be a long term menace to society with your disrespect of the law, the judge, and illegal drinking, and most judges are going to be intent on waking you up to reality.