Impossible to give any concrete answers to this question. I always advise my clients to seek treatment when they are looking at a difficult case like this (I have no qualifications to diagnose anyone with an alcohol problem, but I know that anyone with 4 DUI cases has a problem that needs to be addressed). While being in an intensive treatment program is unlikely to make a judge deviate from a mandatory minimum sentence, being in treatment should make it less likely that the judge goes above and beyond that sentence to "send a message", and make things even worse. I have seen cases where defendants can get day-for-day credits for in-patient programs (very expensive, and more time away from family).
I would seek treatment now. Not only because it is the right thing to do, but because it can limit how bad things can get (for instance it could be the difference in what type of credits the judge authorizes while in custody). Most importantly, he needs the services of a good DUI lawyer! Use the "find a lawyer" tab here on Avvo, and get him in touch with someone who can give specific and confidential advice.
Treatment will, under any circumstances, benefit you personally and when it comes time to try to resolve your case.
No legal advice is given here. My responses to questions on Avvo are never intended as legal advice and must NOT be relied upon as if they were legal advice. I give legal advice ONLY in the course of a formal attorney-client relationship. Exchange of information through Avvo's Questions & Answers forum does not establish an attorney-client relationship with me. That relationship is established only by joint execution of a written agreement for legal services. I am only licensed in the States of California and New York and the District of Columbia
You should do your treatment now as it may help down the road. It likely will be required of you anyway once your case is done. At least this way you can show you are being proactive and if this is your 4th DWI you probably will benefit from some counseling. Good luck.
It seems to be the consensus that you start treatment now. It is tempting to rationalize it and put it off, but that will increase the risk that you will drink again. If the court becomes aware of that, you will surely be facing maximum punishment. Best of luck to you.
The response I have provided is general in nature, and does not create an attorney-client relationship. My practice is based in Rhode Island, and the law and practice in other states or jurisdictions may be different.