Im a bit disappointed you didn’t run your experiment for the whole winter. I have a bunch of trichocereus testing grew from seed plus some larger older ones all sheltered on my back deck. I’m hoping they can handle this winter next week especially) they are completely dry since they are under a roof but they are completely exposed to the cold— so far it’s gotten down to 14 degrees. But next week the low is 8. I found your video while browsing YouTube for hope that this will work and all the time I put into my 4 year old seedlings won’t be ruined. They look ok so far…. Debating putting a frost blanket over them next week but I don’t think it will help—- I tried this with only my larger hybrids last winter and they all survived but I don’t think it got quite as cold as this upcoming week especially