Iirc, growing up Dick and his parents were always with the circus, apart from when it was the off-season where they would spend their summers in Florida and their winters with relatives (relatives in the Rom sense, which meant that everyone his parents age was introduced as an aunt or uncle, kids were always introduced as his cousins, and the elder generation were always grandparents) in Europe.
So I assumed that it's either a. a writer mishap! or b. Tim's home. My reasoning? (it's adorably fluffy) Right now in canon Dick is going to be missing his little brother like woah. Tim was fascinated with the Flying Graysons when he was a li'l kid. And Tim grew up in a nice big house in the same neighborhood as Bruce, in NJ, where snow happens.