I just discussed your post with my daughter as I could not believe the number of trips the school say they do. She confirms what I thought.
There have certainly never been class trips to the theatre for example and there are no trips abroad or anywhere else for that matter than are freely available, even subject based trips. She has never been on a school theatre trip or even a trip to a gallery despite being Art Aptitude (she was expected to visit them herself however).
She is aware that the school occasionally gets theatre/opera tickets but only a few hand picked students can attend.
The Vivo trips are available to about a dozen children who win the annual prize only and are often the same as the perfect tense winners. There was a trip to Barcelona but it was about 3 years ago for the winners only. A trip to Paris and Italy was also for those children only in certain years. The overwhelming majority of students will not come into this category.
There was a weekend in Berlin that ran for GCSE history students but that seems to have been dropped. Business students went to Disneyland Paris for a weekend. There are no language trips to France or Spain that she has heard of. They definitely did not run to Spain.
She has not heard of a ski trip or a trip to Iceland (though one ran about 3 years ago subsidised by the Trust).
The choir trip to Paris was a weekend only and was definitely not available to all.
Flatford Mill is a revision course for borderline students - again these are selected by the school.
Please do not send your child on the basis they do loads of trips because they do not. Unless of course you are counting on your child being in the top 0.01% of points winners.