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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is permissible for one, man or woman, who is in a state of Janaabah to leave home before making Ghusl. It is narrated that Abu Hurayrah said: "The Prophet, sallallaahu ‘alayhi wa sallam, came across me in one of the streets of Al-Madeenah and at that time I was in a state of Janaabah. So I slipped away from him and went to make Ghusl. On my return, the Prophet, sallallaahu ‘alayhi wa sallam, said, 'O Abu Hurayrah! Where have you been?' I replied, 'I was in a state of Janaabah, so I disliked to sit in your company.' The Prophet, sallallaahu ‘alayhi wa sallam, said, 'Subhaan Allaah (Glory be to Allaah)! A believer never becomes impure.'" [Al-Bukhari and Muslim]
Nevertheless, it is not permissible that one delays Ghusl when the prayer's fixed time is due.
Allaah Knows best.