We have tiles and to be honest with kids, it is practical as they spill stuff, splash water out of the bath etc. Yes, it is cold in winter but I either wear socks or slippers around the house and I don't spend that much time standing on the tiles. I don't actually find Melbourne that cold so it doesn't bother me really.

Growing up in cold Ballarat we had cork tiles on the bathroom floor which were warmer and I think wood or lino would also be warmer. The added benefit is that things won't smash if they are dropped on the floor like tiles - and there is so much stuff in the bathroom that can break or smash if dropped on tiles! Carpet would get wet and stinky I think although you might be able to get stuff these days that is designed for wet areas but in my mind I'm seeing 70's shagpile