Hmmm. Hard one Ferrero. I feel for you right now.
What's coming to mind is a thread that Mal started some time back about dogs in the tropics. I think he was referring to Husky's and Malamutes and dogs with those types of coats. Now that would be intersting for you to look at.
I am under the impression that the Newfie can be quite a lazy dog compared to many other breeds, and is quite happy just wandering around inside with it's owner for a majority of the day.
I wonder what Newfienuts opinion on this may be, as she actually HAS George, and has done so for nearly 2 years, with hands-on experience.
Another hard point is that the breeder is not happy to see a Newfie in that type of climate, so unfortunately that carries a lot of eight also.
I'm from Qld, and the heat is a killer. I couldn't survive on the Fraser Coast, little own Cairns where it swelters.
Oh dear, Ferrero.