We left at midnight from Crystal Palace to get on the 7am ferry if I remember right. Leave some time to navigate the hellscape that is Portsmouth though - we were doing 35kph through backstreets trying to find the terminal...
Going back through Whatsapps there's an all-night Esso at about 50km in, if you use the same route - v near Gatwick iirc, and another garage at about 130km just before Portsmouth.
We left at midnight from Crystal Palace to get on the 7am ferry if I remember right. Leave some time to navigate the hellscape that is Portsmouth though - we were doing 35kph through backstreets trying to find the terminal...
Going back through Whatsapps there's an all-night Esso at about 50km in, if you use the same route - v near Gatwick iirc, and another garage at about 130km just before Portsmouth.