I used to do 'overnights' at Derby train station quite frequently after going to gigs at 'The Flowerpot', got it down to a fine art using a rucksac with my little camping stove and a bottle of Single Malt. I got approached by a couple of transport police once who inquired what I was doing (I suppose I did look like a 'down and out') but I explained and they went away quite happily when I told them I was waiting for the train at 4;45am and yes I did have a ticket
(the London - Sheffield 'Midland Mainline' Trains parked up overnight in Derby for refuelling and cleaning)
As they walked away one of them commented on how well prepared I was.