A couple days ago I talked with Butch from the Rowland Collection down here in Garden Grove. He says that there's a Vanda tricolor in Solana Beach that fairly regularly tolerates temperatures below freezing. When the temp hits 29 degrees the owners turn misters on that encase the orchid in ice.
Both
Roberta Fox and
Don Brown also grow this one outdoors year around.
A member of the
Orchid Society of Southern California has also been growing Vanda tricolor outside year around for many years. Personally, my Vanda tricolor v. suavis had no problem with this last winter's low of 33F and bloomed ok...
An orchid grower down in San Diego has been growing Vanda javierii outdoors for several years. It was the first time I'd heard of anybody growing that particular species outdoors here in Southern California.