Here’s a response to that GardenWeb.com posting from someone who lives in zone 6 in New Jersey:

RE: Camellias in Zone 6 (Utah)?

Posted by: ermazi z6, NJ. (My Page) on Tue, Mar 21, 06 at 17:23

April series could be what you need. However, they do not flower from Jan. to March in zone 6, instead they may just start flowering at the end of April.You need to set some protection on them for the first few years. And you may also need to find some acid compost under old, big pines to change your soil.

Here’s something from the Camellia Forest website about an April series camellia that is particularly hardy:

CF`April Rose’ (`Bernice Boddy’ × `Kumasaka’; CF-31) – This very compact and relatively slow-growing plant has rose-red formal double flowers. It has a heavy bud-set and a medium to late season of bloom. After the severe cold of January 1985, this was the only Camellia, among thousands in our collections, to open flowers to any degree, and cold-induced dieback was not recorded in any of the three individuals in our test plots. $22.00 and $48.00