Oh boy.. It all depends on what orchid and what is the temperature you keep it. If it is warm, they still need some water or they will just dry up. I don't think they would ever get bone dry in nature being attached to the tree. It is always some condensation around, some fog or mist. Not exactly the same as in rain season, but something.
I water mine less when I see they stopped growing which is probably around Halloween and start to give them more water when I see buds forming. But I never stop completely and I still give them a little splash like once a month. Not soaking like I do during the year.
The temp in winter is probably around 15 degrees.
That’s what I thought too, but since her approach worked better than mine, I gave it a go with a disastrous effects 😂
Oh well, maybe I misunderstood her advice. Maybe she does the same - water them just a little 🤷🏻♀️