I live in New Zealand ( go down to Australia and turn right) and it is summer here at Xmas time. Most of the early settlers from 1830 on were British, and many of us grew up hearing the old people referring to Ireland, England or Scotland as the Old Country and Home. So there is a strong British influence on the culture. Many of us still cook a roast dinner, often with lamb and mint sauce with new potatoes and peas out of the garden, with mint sauce from the mint bed. We have a pre-ccoked Xmas pudding - my Mum used to boil ours for 3 hours but not me. For dessert we also have trifle, pavlova and ice-cream, with strawberries out of the garden. We'll drink beer with the meal, later on a cup of tea. The younger generation often shrugs off the old conventions and have a barbeque, or even lemonade and tomato sandwiches at the beach.
There are contemporary Xmas cards available depicting accurately a NZ Xmas scene, but the usual pictures of snow, sleds and holly are very popular. It takes a long time to change a tradition.