I live in New Zealand and there are many 24/7 McDonalds in busy areas. Clicking randomly on their NZ map it's pretty easy to find them: https://mcdonalds.co.nz/find-us/restaurants

It's the same with Australia: https://mcdonalds.com.au/find-us/restaurants

Actually, the same for the US. It's not hard to find 24/7 ones (you need to search for a city before they show on the map): https://www.mcdonalds.com/us/en-us/restaurant-locator.html