Is there a train big enough to get them all from Kings Cross to Cleethorpes though?
Best if it's just the 2 of them, will make it much easier to get the train tickets.
You can bank on 30 mins queuing for a train after the game.
If you're travelling on the day of the game, you need only buy your ticket to Haywards Heath. From there to Falmer & back is covered by your match ticket.