Magistrates’ sentencing guidelines for a first time offender with such a high level of excess alcohol suggest a “starting point” of 12 weeks’ custody. Depending on the circumstances I would say that a second offence would almost certainly warrant more than this, possibly up to the maximum of six months. However, if a guilty plea is entered at an early stage a discount of one third must be allowed, making the likely maximum 4 months.
A second excess alcohol offence within ten years of the first attracts a mandatory minimum three year disqualification. With the level of alcohol in this case that is more likely to be up to five years.
The magistrates are not obliged to order a re-test at the end of the ban. However, in the circumstances you describe it is highly likely. The driver may also be required to satisfy the DVLA that he does not have a drink problem in order to regain his licence. This would most likely be by interview and medical examination. This is not an order that will be made by magistrates but one that will be imposed by the DVLA when considering his application for a new licence.