We can watch the trailer in the UK via imdb, but not see the full film without fooling our place of residence; as far as I can see.
I went there a few years ago with a local resident. Saw no others there on that day. Contacted Frank Cabot after and thanked him for a great garden visit and happened to mention I had seen a large number of Cypripedium earlier in Ontario. He replied that had he been there he would have taken me into the local forest and showed me 100's. There is a long narrow vista through trees into a local field which was occupied by a number of cattle. He told me they put feed there to attract the cattle to the right position ;-) It had one isolated point among the clipped hedges where an orchestra of oversize frogs start playing when you approach.
Don't think there was many alpines but a super place to visit, especially on your own, although that rope bridge was a bit scary with no-one around to pick you up if you fall.