I’m not one of the staff and also actually don’t know when school holidays in UK begin, but maybe this Bwtcamps 2019 might help. At this particular link it’s the date for July Bootcamp and if you scroll down there might be more info. The main info is at the beginning of the topic (the original - first post - a few posts upwards).
However, looking a bit closer the July Bootcamp is sold out already but the June bootcamp might still have one place available despite it was announced already 6 days ago.
Hope, until Iestyn finds the time to answer, you could find some solution in these threads.
After these two bootcamps it’s usually one in September also if there are enough people interested in it but the school begins too already, doesn’t it.
Hwyl!
Tatjana 