August & September busy times. Theres no availability if you can’t see any, as it’s a popular route and once the allocated amount of reward seats are taken, there’s no guarantee any more will be released. Lots more help and the excellent FAQs in the main thread in this https://www.flyertalk.com/forum/brit...er-thread.html

You can always try and book last minute, but most people want more concrete plans.

Id suggest somewhere else or paying cash.