Anyone still cut off from power following the recent storms is unlikely to have it restored until Boxing Day, the Energy Networks Association says.
About 50,000 homes are without electricity in the east and south-east of England after rain and wind lashed the UK in the run-up to Christmas.
Flooding caused disruption across England and Wales, with 150 properties flooded – mainly in Surrey and Kent.
Two severe flood warnings remain in place in Dorset.
The warning – meaning there is a danger to life – is still in place for Iford Bridge Home Park on the River Stour in Dorset, which police evacuated overnight.
Liz Gaere, 48, was rescued from the residential development at around 07:00 GMT on Christmas morning.
“We went out on our balcony and saw the flooding and saw the boats coming in,” she said.
“They said to us ‘do you want to come out, you’ve got five minutes’.”
A 79-year-old neighbour Pat Tapply added: “I have nothing apart from what I am standing in. I don’t know if my home is flooded.”
People were also evacuated from the Beaulieu Garden Park Home in Christchurch, Dorset – where a severe flood warning is also in place
However, Mr Field said areas still experiencing power cuts would need major work and many were also in areas that could not be reached due to flooding.
UK Power Networks, which supplies about eight million customers in the South East, says it arranged Christmas dinner for hundreds of those without power via a mobile catering facility, pubs, restaurants and hotels.
Meanwhile, about 800 homes in the north of Scotland are still without power, mainly around the Banchory, Buchan and Aboyne areas in Aberdeenshire, and Forres and Fochabers in Elgin.
Scottish Hydro Electric Power Distribution said it was hoped all properties would be reconnected on Christmas Day.
Christmas dinners disrupted
Some of the worst disruption was felt at Gatwick Airport in West Sussex, where a power outage at the North terminal led to cancellations and delays on Tuesday.
Gatwick Airport is now running a full service, but says all flights apart from those with British Airways will be departing from the South terminal. It also advises people to check with airlines before travelling.
The Coastguard rescued 76 people from a flooded caravan park in Yalding on Christmas Eve, moving residents by boat and in four-by-four vehicles to a leisure centre.
In Surrey, residents were evacuated from their homes in Dorking, Leatherhead and Guildford, while more evacuations occurred in Tonbridge, Kent where the River Medway has continued to rise.
Wiltshire Police say the historic Lacock Bridge has been washed away in the bad weather.
Some 40 properties were evacuated in Godalming due to concerns about the River Wey.
Firefighters in Surrey and Kent broke a five-hour nationwide strike to help deal with the effects of the storms.
Kent Fire and Rescue Service said its control room received 130 calls between 05:00 GMT and midday, and reminded people to ring only if there was a risk to life of serious property damage.
One hundred people booked in for Christmas dinner at the Wetherspoon’s pub in Tonbridge, Kent had their plans disrupted after the restaurant flooded and managers had to send customers elsewhere.
Distributor UK Power Networks is offering to pay for Christmas meals in local pubs or restaurants for people whose supplies remain cut off.
On the roads, many major routes were flooded or blocked in Kent, Hampshire, Surrey, Sussex and Cornwall.
In Dorset, fire crews rescued 25 people trapped in their cars by flood water.
The Isle of Man Steam Packet ferry crossings says it is taking the unusual step of operating a Christmas Day sailing following cancellations on Tuesday.
Airline easyJet says it is operating a limited number of flights from Gatwick Airport to replace ones that should have operated on Christmas Eve.
Southern Electric said some 19,500 customers, most in south Hampshire, Surrey and West Sussex, could remain without power overnight.