In most cases, a person will not go to jail for drink driving. It is always the maximum penalty available.
However, jail is definitely a possibility, and drink drivers regularly get sentenced to a term of imprisonment.
As a general rule, you are more likely to be imprisoned for drink driving if you have a prior history of high-range DUI offences.
You are also at serious risk of imprisonment if you injured someone or caused property damage because of your driving.
Importantly, a court must impose a period of imprisonment if you are convicted of a 3rd high-range DUI offence within five years.
It does not mean, however, that you automatically go to jail. The court can wholly suspend the jail sentence or grant immediate parole.