alessandro, many orchids also experience worst case scenarios in their native habitats! Here's a passage from "The Orchidaceae of The Bahama Archipelago - Taxonomy, Ecology and Biogeographic Patterns"....

Australia, Brazil, China, Mexico, etc. all experience temperature and moisture fluctuations. For example, an orchid grower in Brazil wrote to me that Cattleya tenuis experienced a 7 year drought in its native habitat. The problem is that we haven't been monitoring the extreme temperatures where most of the epiphytic orchids grow as long as we have been monitoring the extremes in more developed countries.

alessandro, here's my list of eurythermal and fragrant orchids.

A decade plus on, I've found great benefit from this post and others of yours. I'd love to know how the ones you were testing fared.

Im really late to the party and not a very experienced grower but Im happy to add the plants I grow.

I live in South Australia, an hour South of Adelaide in a coastal town called Victor Harbor (yes the USA way of spelling harbour)

We don't get the extreme temperature highs experienced by Adelaide. They can get 37C to 45C (98.6f to 113f) sometimes for a week at a time and this is a very dry heat.

Here we get the occasional day with the high temps with the dry heat just like Adelaide but in general temps here are mid to high 20s (75f to 84f) in Summer and probably 5 to 7C (41f to 44f) in Winter.

I found a reference that said the climate here is classed as Csb by the Koppen-Geiger system, if anyone else has knowledge of this weather scale. I will look more into this K-G system myself.

I live a klm from the sea facing open hills where the prevailing wind comes from.
I grow outside under a verandah.
I grow mostly hybrids, Cyms, Dendrobium, got a couple of speciosum growing from cuttings, but they are very slow.
Cattleya, Oncidium Alliance, Sarcochilus, Epidendrum and Tolumnia.
My Sarcs are in a Leca type media which Im planning to change as I feel they dry out too quickly. The rest of the above are in either medium or small bark.
Apart from the Cattleya, which are not big enough to flower yet, everything else has flowered outside.
I have deflasked Tolumnia, mounted them and they are hanging outside. Last night was 9C overnight. So far Im really happy with the way they are growing, they have new fans so hopefully there are new roots behind the moss.

I'm happy to hear a Tolumnia can handle the SA outdoors, I thought our cool nights wouldn't agree with them. I might try popping one of mine in the shadehouse and see how it goes along with the Onc intergenerics I'm experimenting with.

I'm actually doing the opposite in moving my Sarc's into leca after seeing Kevin Western's nursery and all of his growing in that media (and nearly losing one I bought at a show to root rot).

Im worried about the cool nights too, Im hoping with shadecloth at the back of the shelving (Western side) and on the side (North side) plus the house (Eastern side) and a protecting hill on the Southern side they might be ok. Im willing to take a risk with them as I have quite a few.

Edited...
Forgot to mention the Sarcs. I got mine from Kevin Western too which is why Ive left them in the media they came with as he seems to have great success with the expanded clay ball media. Maybe Im just not watering enough.

Initially I thought that the cold was going to be the biggest factor, but then it turned out that the orchids that have done the best for me are the drier growers.

Hi I grow outdoors only without protection other than the eaves. A lot of my orchids are hanging under eaves on the shady side of the house and the sarcs and docks are doing well