Two big bushfires between Canberra and the South Coast - the Currowan and Tianjara fires - have joined into a single fire stretching 80 kilometres from just north of Batemans Bay up towards Nowra. They have been downgraded to advice, and fire activity is easing.

But the RFS has upgraded the Comberton fire, burning near Nowra, to emergency status. It has burnt more than 1000 hectares and is currently out of control.

The North Black Range fire to the west of Braidwood was under control on Monday, albeit with occasional spot fires.

Rural Fire Service deputy incident controller Angus Barnes told a Batemans Bay community meeting that the remote terrain of the Currowan and Tianjara fires meant they were particularly difficult to contain.

"We're looking at weeks of firefighting ... it's currently in a very remote area," he said.

"We can't get people in close to it to try and address it without endangering their safety."

Ultimately, firefighting operations were weather-dependent.

"In all honesty, the only thing that's going to put this fire out is rain," he said.

Although conditions are forecast to ease over the coming week, NSW Rural Fire Service commissioner Shane Fitzsimmons has painted a grim picture of the longer-term weather outlook for NSW.

"We've got to keep in mind that we're not expecting any rainfall to make any meaningful difference to these fires until January or February," he previously told reporters.

"That's still a way to go. We're still talking four to six weeks at best before we start to see a meaningful reprieve in the weather."

The NSW Rural Fire Service is still determining the damage from bushfires that tore through NSW over the weekend, but it's believed another 100 homes could have been lost, including some on the South Coast. It says there has been a "significant fire impact around Nerriga and Sassafras".

Mr Rogers said more than three million hectares had burnt this fire season.

"It's an enormous amount of the landscape and forested areas," he said.

"We shouldn't underestimate just how much of the natural environment is being burnt and that's got serious ecological impacts as well as the fire impact ... I think that'll be felt for years to come."

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Mr Barnes told the community meeting the Currowan and Tianjara fire was not threatening Batemans Bay.

"Rest-assured at the moment it's a long way from the bay," he said.

Eurobodalla Shire Council standing general manager and local emergency management officer Warren Sharpe said crews were faced with a big job.

"Now it's crossed the Kings Highway, it's burnt back from where it crossed, above Government Bend back to Cabbage Tree Creek, cross all upon the Kings Highway," he said.

Bega MP Andrew Constance said it would be probably be weeks before the highway reopened.

"I can only be guided by Transport for NSW - and through Warren [Sharpe] - as to what we're dealing with. It'd be nice to open it now, but the reality is it's too dangerous," he said.

Eurobodalla Shire Council mayor Liz Innes told the Batemans Bay community meeting there had been incredible examples of the community helping out, and she asked residents to check in on neighbours.

She said it was best for residents and visitors to support shire businesses throughout the holiday season.

"As a community, we will get through this," she said.

In tears, councillor Innes asked everyone to put their arms around volunteers who were putting their lives on the line to keep everyone safe.

In question and answer time, a community member asked whether the Princes Highway opening meant there was no danger of falling trees.

RFS member Kelwyn White said people who had planned to go to the South Coast over the holiday period would have to decide individually whether they would still visit, especially given the Kings Highway was closed and the Princes Highway had closed and reopened a number of times.

"It's Christmas. People want to spend time with their family and friends. It would be heartless to say 'Don't come', but they need to be aware of what they're coming in to: We have a really large active fireground," she said.

"So, if people are coming into this area, we will have deteriorating weather conditions again. We may see more impact into our community.

"I definitely can say we will see more smoke again, which has been unpleasant.

"It's a personal choice. Monitor the conditions, make sound decisions, check the information before you decide to travel."

The ACT Emergency Services Agency published video taken from a specialist helicopter showing fires around the highway near Government Bend.

with AAP