All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
Zakat Al-Fitr is an obligation and a traveller is not exempted from paying it, and has to pay it whenever it becomes due regardless where he happens to be at the time. Therefore, you have to pay Zakat Al-Fitr in the town where you are at the time it becomes obligatory. As for your wife and children, you have to pay Zakat Al-Fitr for them in the same country where they are.
Allaah knows best.