Relationship manager Danny Gough said that based on limited access to the biggest areas impacted by network devastation, it looked like customers could be without power for over a week.
The crews' efforts were restricted yesterday by the lack of access to cross-country areas, where most of the damage to the 33kV network is.
"We have been working with Taupo District Council's Civil Defence Emergency Management team to organise clearance priorities for access, and working where we can with limited access," Mr Gough said.
Until access was cleared, the Unison team was sourcing materials and organising support so restoration efforts could begin swiftly.
Crews were also working to restore power in rural, high country parts of Hawke's Bay yesterday.
After assessments, Mr Gough said they were encouraged that the majority of customers could have power restored in a few days.
"As we dig through by foot, we are uncovering more damage, so restoration will depend on how much more we find."
Those without power were said to be coping well.
A team from Hawke's Bay Civil Defence Emergency Management Group and the Hastings District Council spent yesterday in hill country north of Napier, visiting farms to assess the situation, and what assistance was required.
Hawke's Bay Civil Defence Emergency Management Group Controller Ian Macdonald said staff reported that while there was a lot of snow around, the affected people were well prepared for such an event and supporting each other.
Some families had chosen to "self-evacuate" for the night, but generally people were staying put and staying warm.
Read more:
• Wild weather leaves families without power for at least a week
• Editorial: Power cut a timely reminder
Mr Macdonald said Hawke's Bay CDEM Group was putting plans in place for people who may need assistance in the coming days.
They would be visiting the Puketitiri area today to see how farmers were coping with their stock in the heavy snowfall.
Although most closures have been lifted for roads around Hawke's Bay, the NZ Transport Agency was advising motorists to drive with caution and to the conditions.
State Highway 5 remained closed overnight, with an update expected at 10am today.
Senior Sergeant Nigel Hurley, of the police Eastern District command centre, advised motorists to drive with caution.
"In Hawke's Bay we don't often get events where there's areas of ice on rural roads. If there has been a frost and the road looks wet, it may be black ice so be careful."
Yesterday Metservice meteorologist Peter Little said the worst of the weather had passed for Hawke's Bay, which was now in the "easing phase".
In the 48 hours over the weekend, the highest rainfall was 206mm in the ranges north of Napier. Hastings received 75mm, and 67mm was recorded near Hawke's Bay airport, meteorologist Claire Flynn said.
In the Takapau plains, only 25mm fell.
Showers and cool temperatures were expected for the rest of the week, with a mainly fine day on Friday.
- A public meeting will be held for Unison customers at the Rangitaiki Tavern at midday today.
- If anyone in these areas is in need of assistance they should call the Hastings District Council on 06 871 5000. If they have power concerns they should contact 0800 2 UNISON (0800 286 476).
- Assistance and support is also available for farmers from the East Coast Rural Support Trust.
