I bought 2 China Curls and 2 Escargot begonias and hung them in a super fancy iron basket with water-holding husk liner in San Clemente (Southern California: well outside the plant's suggested zones).
All four begonias appeared to die in the spot I placed them, so I moved them to a very shady area and a couple months later, both the previously barren China Curls came back with a vengeance but I'm unsure the 2 Escagot begonias ever will (I can see the tiniest of leaves on the stem of one of the planted escargot bulbs). The China Curls are absolutely stunning and I get a lot of compliments, as these humid-loving plants are a rarity in arid Southern California.
I highly recommend them and suggest you hang them with a water-storing liner in a super shady spot (if you're in a climate like mine) and water often. :)