I don’t think that climate decides whether to go hybrid or not. It is just a question of whether you want comb honey as well as extracted honey.
However, your question raises an important point. Flow have not really done a good job of explaining that there is nothing special about their hive design that requires you to have just one brood box. Here in California, most hobby beekeepers run their hives with 2 brood boxes, because we have very long nectar dearths when we don’t get rain for long periods. It is not the temperature, just the dryness. In the Northern US where the winters are cold and long, many people use as many as 3 brood boxes, even those with Flow hives.
My understanding is that many Australia beekeepers in colder areas use one deep and an ideal or WSP for overwintering. I think you may find that better than a hybrid Flow super.
As far as hybrid vs full Flow goes, I answered that here: