They Said That It Couldn't Be Done...
...and that seems to be the rationale behind some efforts at Tropicalismo.
In David Francko's book "Palms Won't Grow Here and Other Myths", the author takes great pleasure in describing techniques for overwintering tropicals that historically have never been considered as permanent landscape subjects in non-tropical climates. Typical is his discussion of getting Chinese fan palms to survive a zone 6 winter and seeing "a few beautiful palm fronds" generated in the following season.
I have to wonder about the point of some of these struggles. Is it really worth it to construct enclosures, buy and use antifungals, antidessicants and heating cables, and otherwise utilize elaborate strategies to overwinter tropicals that in the end, are pale imitations of what can be achieved in the right climate?
In the case of the Chinese fan palm, I used one in a border this past year. Before frost, I dug it out and it is overwintering in a low-light location between fluorescent light stands in my basement (it did well under these conditions last winter) before being returned to the border next year. And if this doesn't work out, there are more good-sized $6 fan palms available at the local building supply store nursery department.
I do overwinter bananas, crepe myrtles and Nandina here with minimal low-tech protection because they achieve substantial decorative effects in my climate (the crepes will likely never become trees, but they should flower abundantly with a shrubby habit suited to my space, and 8-10 feet of banana growth in a season is plenty enough to convince me that I have temporarily relocated to the tropics). However I can't convince myself that it's worth a major effort to raise a spindly palm or stunted live oak, merely to show that it can be done.