Just for a laugh, I did a search, and this is the first link that popped up.
In big red font it says:
Private/non-government school holidays often vary from state/government school holidays.
There is no definitive set of school holiday dates that applies to every private school.
Please check with each individual school for accurate dates.
So pretty much what I am getting from this; where ever you plan to travel, the onus is on you to plan out and check with every private school that is on your path to your destination.
What a pain in the arse. If private schools get to deviate their holidays from public schools, shouldn't they be the ones to be informing the general public?