Modellers are predicting between 460 and 1450 people will die from Covid-19 in the Omicron outbreak.
Latest data modelling from Te Punaha Matatini, which the government regularly relies on, has been released, showing a wide range of scenarios because the variant is so difficult to model.
The best case scenario is based on South Australia, which has similar public health measures to New Zealand, and assumes that 90 percent of the country is boosted.
That could see about 800 people in hospital at any one time at the peak of the outbreak.
About 1.5 million New Zealanders would be infected, but fewer than a quarter of them would be identified as cases.
But in the worst case scenario, based 70 percent of people being boosted, and a rate of transmission similar to New York, 3.5 million people would be infected, with 895,000 of them identified as cases.
Then, there would be about 4200 people in hospital at the peak of the outbreak.
Te Punaha Matatini's Audrey Lustig said even the lower end of the scenario would place a significant strain on the country's hospitals and intensive care units.
The researchers emphasised how important boosters were to preventing death and hospitalisations but said there were questions about what could happen as the protective effects wear off in the coming months.
To date, 1,605,815 people have received their booster doses - 57 percent of those who are eligible for one.