I think the studies you referred to are so limited in their scope they cannot be taken seriously.

“We’re just looking at human production systems. But depending on the size of the war, you would also have natural systems collapsing. So those sorts of things aren’t considered,” says Heneghan.
http://cosmosmagazine.com/earth/nuclear-war-winter-australia/

Good that the article you quoted mentioned an influx of people from other northern nations.
Sad that you didn't consider the fight for food resources (and water under a dramatic increase in population) would result in people eating other people.
Good that it mentioned fuel limitations and an inability to distribute said Australian grown food around the country.
Also, you failed to mention foreign governments would likely send their people and families to Australia, and they would live in guarded compounds hoarding resources while Aussies eat one another.

Finally, very unrealistic to not mention the hoarding of food supplies by richer countries and wealthy elites, a very realistic scenario if you take the Ukrainian grain situation into account.
People will be starving in the streets whilst others will be hoarding years of supplies for themselves.

Chaos would rule.

Prevention is better than a cure.
It would be far better to have an honest sobering look on how we got to where things are now and what we can do to prevent these scenarios from ever taking place.

I blame US foreign policy.

"It MIGHT go something like this', pants the narrator/actor in this 4.08 minute video, speaking in the present tense to make it spookier. Typical of the scare-mongering-listen-to-us-or-look-out variety.

In depth too: how it would be in all of 4.08 minutes! Based on "detailed modelling". We all know about ' modelling' from the covid ballsup, and the climate scaremongering.

To someone who wants the media to "shape news" (it already does), I say bullshite!

I don't want my news shaped.
Just tell the bloody truth.

Interesting he talks about this nuclear war scenario as a foregone conclusion.
"How will Australia fare when a nuclear holocaust takes place?'
- Not 'IF but 'WHEN'...

Get a real job you loser, your commentary isn't worth anyone's time.
Go do something useful if this is a topic you care about, like support Non Proliferation Treaties or weapons inspections, and criticise the US government who enrich themselves from war and chaos overthrowing other countries for 'democracy and human rights' i.e installing their own puppet rulers, stealing nations resources, stealing foreign talent to ensure technological and financial hegemony, enriching themselves from the arms, financial and pharmaceutical industries.

I would have thought Lim Teck Gee would be more interested in what would happen in Malaysia, where he "is a political analyst" according to his biography.

We could have a nuclear winter about three years long. and some radioactive fallout to our north?

Those with double glazed glass houses may be able to feed themselves. Others, preppers with huge reserves of canned and frozen food may manage?

Our government sits on its hands consoling themselves that they will be ok! And have no plans for a food bank! Or any other contingency. As that might eat into food export dollars!

Those of us who can, should prepare as best we can for the inevitable, as there is a madman with an itchy finger on the nuclear trigger! And may use before Christmas?

Row, row your boat merrily down the stream. Merrily, merrily, life is but a dream.
Alan B.

If any major conflict brakes out, nuclear or conventional, the first thing that happens is our transport fuel supply is disrupted. No fuel, no food deliveries to our cities. Millions die from starvation.

Those with horded supplies with in reasonable distance of cities are taken over by starving mobs.

The first thing we should do is force anyone who wants to supply liquid fuels in Oz to harvest our huge supplies of shale oil, & refine it here in Oz.

The second thing is to develop modern coal fired steam locomotives to ensure we have rail transport without imported fuels.

After that, eliminating imported power generating equipment, & developing a capacity to again build power generation equipment again in Oz. How long is it since we built our own power house equipment, or rail rolling stock, & how long would it take to redevelop such industry?

Without these actions we are at the mercy of idiots controlling other countries.