We got to Calais around 4 and were talked into going to the terminal and buying tickets for later while the queue was short (we got to the window just before a coach arrived) and then sleeping. That put us on the 1.55 sailing as we declined the 5am and 11am. It was have been the crush they've had for 2 days this morning or it may have been as quiet as this afternoon. I'm sure we could have done lots of things on the way but if we'd done them and not got a ferry today (we saw dejected folk walking away but not many) we would have been furious - and Amex said they got us some of the last rooms in Calais. Travel lottery - and we have a hugely busy week.
If you know anyone trying to get back, turning up at the ferry terminal is the best option and nowhere as spirit of Dunkirk as you'd expect.
Oh and Google Maps: you can navigate well enough but you always put businesses in the wrong place. At 4 in the morning sending me right when my hotel is two blocks to the left is bad and I'm always going to prefer a service that has paid for accurate location information. Kthxbye.