SpecialPatrolGroup: Oscar's sister, Charlie, lives in FNQ. In Townsville. Her owners were living in Melbourne but moved up there because one of them is in the military.
She's fine. I'm pretty sure Oscar would be fine anywhere as well as we keep him fit and healthy. Those that show English Bulldogs tend to keep them overweight because the breed standard says they look better that way and the fatties tend to do well in dog shows. This is a massive factor in how well they tolerate the heat.
Barney on the other hand would probably struggle heaps in the heat so it would all be about choosing a healthy pup and taking a good look at both parents. Also, breeders in QLD would have dogs that are used to the climate so you should be okay.