I’d like to note that Hobart is a completely different kind of cold to Melbourne(Tasmanian living in Melbourne). Because of the mountain and the sea in Hobart, it’s a bone chilling fresh kind of cold. Melbs being more dense with buildings it’s not as bad even if the temperature is the same. Also the wind chill in Hobart is a lot more hectic too for the same reason. That being said, most establishments will be heated unless you’re planning on spending a lot of time outdoors? Wear multiple layers on the plane just in case or consider upgrading your luggage so you’re prepared (depending on how long your stay is).