'Has anyone had their emus successfully hatch any eggs?'
Planet Rothschildi here in Western Australia -- Rothschildi territory -- has observed two hatches: Boy Emu and Noddy Big Ears.
They don't need food or water. They don't poop.
Emu species in Australia hatch in the wild in some very cold places -- right up to the foothills of the Alps. But we don't know what sub-species yours are. The desert sub-species, woodwardi, certainly don't encounter cold weather during incubation.
Here in South-West Western Australia, the males don't experience snow; but they do sit still for seven-and-a-half weeks through some pretty wet and wild winter weather. But if your male is healthy, he should have worked up a good layer of fat to 'power' his incubation.
The male's 'curtain' of feathers provides a fine 'seal' for the eggs under him. He will likely stand to turn those every few hours.
Apparently -- I have no first-hand understanding of this, but it turns up in discussions -- young emu males may botch their first incubation through indiscipline.
Folks are entitled to love and pamper their emus; but luckily, emu males are extremely efficient incubators. If you have fertile eggs, and the nest area is quiet, all you need to do is watch and wait. (You won't know, but Dad gets first wiggles about half way through, and peeps in the final weeks.)
I don't suppose a 'skirt' of straw would help. Certainly snow would be my main concern. Even the wet and wild winter weather here is much less severe than snow!
You could start a thread here, and report for us!!
Supreme Emu, Western Australia