Eurostar has opened up its reservation system a little further in advance. Effective this week, you can now book six months ahead rather than just four months.
As few people realise this yet, you might find a few bargains, even at peak times, if you look 5- 6 months forward ….
For some reason, Eurostar is promoting this as a ‘temporary’ event which ends on March 2nd. Realistically, though, I would expect them to stick with the six month window as long as customers are happy to book that far ahead.