I've spent plenty of time in that part of the world.  The track from the bitumen to Peron Station is just hardish red sand, slightly corrugated in places but should be fine.  From Peron on, the track gets narrower and softer, but should be OK if you air down your tires.  There are some tight sections by memory but I'm sure you'll get through.   The Ranger drags a big trackor tires over the tracks to smooth them out which makes a difference. 

Maybe someone has been there in the last few weeks/ months.  Are you travelling alone or with another vehicle?

 have towed a 4.6mtr plaka into most spot on peron there is some soft sand in spots. we drop alot of air out of tyres and never have to much trouble. early morning also helps before the sand gets hot.

The track into Herald Bight is pretty good  until you get to the last couple of hundred meters from the beach  where it can get very soft, its the same with gregory's  it can be very soft ,all depends on who has been churning the tracks up.

The only thing I have noticed is that the bigger boats launch from monkey mia and anchor in Herald Bight .

Thanks for the info fellas.

The plan so far will be to leave both trailers/boats near the homestead, cruise into the decided camp drop the ladies off to set up camp.
Survey the area and decide from there.
 

Hunterdive: There will be at least two other capable 4WD's.