Please have a look at the questionnaire page if you have a spare minute.
Your lucky to be able to book the holidays in the calendar year we are actually in ie book 2019 holidays at work in 2019! When I was at work they wanted to know about your proposed holidays at least 18 months in advance, so I would now be looking at holidays for around June 2020 onwards. Have a lovely time when you go. Not long till March.