The icy conditions have continued to hamper cleanup and aid efforts across the region on Sunday.
NI Electricity says it could take "several more days" to repair damage to the network, after snowstorms caused cable icing and trees brought down lines and broke poles.
Over 140,000 customers were affected in total, with engineers working around the clock since Friday to fix the outages.
However, NIE said small pockets in rural parts of Co Antrim and Co Down may still be off on Monday.
Emergency services including the police, Ambulance Service, Fire and Rescue Service and several other organisations have been coordinating their efforts over the past 48 hours to assist those worst affected by the severe weather.
In one instance the PSNI helicopter had to be used to bring emergency oxygen supplies to a 79-year-old man who was snowed in at his house in Newtownabbey.
Several attempts had been made by local officers to reach him but the road was impassable, and he later had to be airlifted to hospital.
Teams have also been undertaking operations to deliver medicine to those stranded in rural areas such as Glenarm in Co Antrim, where some houses are buried under 18ft snow drifts.
"Last night we mounted a number of search and rescue operations designed to deliver medication in the Glenarm area," Chief Inspector Tim Mairs told UTV.
We're also undertaking operations to extract those ill people from those areas and bring them out for medical treatment because their condition is so bad.
Chief Inspector Tim Mairs
"Over the last couple of days we've seen an increased number of calls from people in isolated, rural communities.
"Particularly down the eastern side of Northern Ireland there has been massive disruption and on higher ground there are communities that are experiencing isolation as a result of blocked roads, loss of electricity and loss of water."
An RAF helicopter from Wales has now been stationed at Aldergrove and is on standby to help the emergency services.
Health Minister Edwin Poots said: "As this difficult weather persists, I would ask the public again to be good neighbours and look out for those such as the elderly, disabled or those who are particularly isolated, who may need help."
Meanwhile NI Water has been working to restore supply to around 500 customers who are still without, mostly on high ground and in parts of west Belfast and south Antrim.
A statement said: "The vast majority of customers are now back in supply, however a number of customers in Antrim and north Down may experience low pressure or interruptions to their water supplies as it will take our water distribution system some time to fully recharge following the interruptions to supply as a result of the power outages."
The snow has also caused severe disruption to the roads network over the past three days.
The Roads Service says snow clearance operations are continuing in high ground areas in the eastern parts of Northern Ireland.
A statement on Sunday evening explained: "The operation of snow clearing on routes in these areas is ongoing with Roads Service plant including snow blowers, snow ploughs and loading shovels being deployed from other areas."
Road surface temperatures are expected to fall below freezing tonight with a risk of snow flurries. Salting is expected to be carried out on all main routes likely to be affected.
The Roads Service also appealed for vehicle owners parked alongside main routes to move to allow clearance machinery to pass safely.
Many routes remained closed due to snow accumulations on Sunday night. The worst affected areas are in Ballymoney, Moyle, Antrim, Larne and Ballymena, in the south Down area around the Mournes and Dromara Hills, in Newtownabbey, Carrickfergus, Lisburn and north Down areas.
Meanwhile NIE said engineers, including around 140 linesmen from the Republic of Ireland and Scotland, are continuing with the restoration process overnight.
"Unfortunately small numbers of customers will be off overnight in isolated rural areas. These are areas that we have still been unable to reach by road," a spokesperson explained.
They are the Ballyvoy area of Ballycastle, areas around Ligoneill, Hannahstown, Stoneyford, Dundrod and Mallusk, Craigantlet - in particular Moss Road, Ballyward, Castlewellan and Newcastle, Buckna, Broughshane, rRural areas north of Carrickfergus and Crumlin.
Roads Minister Danny Kennedy said: "Our Executive Departments are working together during this challenging period to serve the entire community.
"I pay tribute to all the utilities providers including Northern Ireland Water and to Rivers Agency who have been working tirelessly over the weekend to ensure water and other essential services are maintained. I also commend the work of Translink who have worked to keep public transport on our roads and railways."
Northern Ireland's airports remained open; however passengers were warned to expect delays on Sunday.