Wow, thanks everyone, you have been so helpful. Yes both dogs are NZKC registered, though the older one was a re-home from a breeder, so will look at getting her papers.
Also thanks for the advice about the cool covers! Great idea. The heat has been something I have been worried about as we will be heading over about December so it could be a bit of a shock for the girls - and me!!
Many thanks for all your advice everyone, very much appreciated.