As I expect most people if not all people would know Christmas in Australia comes at the start of Summer, it isn't uncommon to have stinking hot Christmas Days.
When I was a child we use to get up and open presents have ham on toast for breakfast, tin ham at that. We then loaded the car up with presents and head to my grandparents house which was only a 3 minute drive.
Christmas lunch was a traditional hot roast meal with turkey, pork, ham (not tinned) and lots of baked veggies followed by plum pudding with ice cream or custard, I don't eat plum pudding but often my nan would give me a a small piece of plum pudding that had a couple of sixpence in it.
Nowadays in my family we don't have a hot meal we do still have turkey, pork and ham (not tinned) with seafood and salads and we don't have plum pudding as the only ones who like it is my parents. We also have either a potato bake or baked potatoes because both me and my brother love baked potatoes.
We have never had a BBQ on Christmas Day and don't know of anyone who has, although I am sure that some people might do that.
In my family some years Jessica and Leo will spend Christmas Eve here with Tim and me and Santa will visit Leo here but I think this year they will be spending it with Kelli and Daemon because Jonathon has to work and Kelli doesn't want to be alone.
If it is just me and Tim here we get up when we wake up and the girls will usually pop over to exchange gifts and Tim and I will go to my parents place and Jessica and Leo will often have Christmas lunch with Kelli & Jonathon or maybe they will just go home and have a quiet afternoon alone. Kathy-Lee and her family usually have Christmas lunch at her home and will visit us and Michael's family during the day.
For many years after we stopped going to my grandparents for Christmas lunch we all went to my parents place but now our children are all grown and have children of their own that has changed and I get why it has changed but sometimes I miss the big Christmas Day lunches.