Greenhouse,
I live in San Antonio, and I expect you have experienced the same "Blue Nortnern" that blew through for us yesterday. We are experiencing our first multi-day span of mid sixties weather!
In regards to putting your plant into dormancy:
finding out whether your Purpera just came out of tissue culture is as easy as asking Phil and Jaie, and letting them know when you purchased it. I have a gut feeling it has actually been out for a while, simply because They are trying to clear out their purpera stock so they can make room for other strains of Sar's this spring (According to their sales page!)
Any how, it is entirely possible that it just came out of TC< and is young enough that you don't need to put it to bed.
My Sars which are all out doors now, (some were moved a month ago) have all slowed down, probably to reduced photo period, certainly not the temperatures, and have massive buds on the end of the rhiozomes, they are going to go in the fridge the minute the fungicide comes in from Phil and Jeff.
While it is true you can lose plants do to rapid cycling into dormancy, I don't think it should be an incredibly large concern, if you are going to wrap them up and put them in the fridge bare root, by taking simple precautions I think you can ensure your plant will survive, but I won't bet the farm on that. There are exceptions to every rule.
Also remember that you may be sacrificing far more vigorous growth this spring, by giving it this vigorous growth period now, and sacrificing formancy.
My personal opinion is some where between going immediately into dormancy, and skipping it, like Mike said, I think if it is OK outside, then I would leave it out there 24/7, And I can pretty much gurantee you that barring a squirrel attack, it will be OK, mine were enduring the 102 degree summer we had in San Antonio this year. Leave it outside, and the reduced photo period will eventually get it through to the plant that it should go to sleep for the winter... then go ahead and go through your dormancy steps and wake it back up next year.
You'll allmost certainly be fine going either route, but here is something to keep in mind, something that San Antonio and Houston share... Brutally hot summers... your going to get your best pitcher growth in early spring, which is most peoples late winter, if your plant decides to go dormant in spring on it's own, well, you just lost your best growing period for the year, cause we both know fall is practically non existent in south texas, summer is almost all year long, and winter, when we decide to have it, is a freaked out almalgamation of all other seasons!
Another thing to consider is that the Big Thicket, which isn't to far from houston, is a natural growing place for Sarracenia Purpera, and once you have the plant aclimated out doors, you might be able to leave it there all year long, I am not sure about how different houston vs. Big thicket temps, humidity, and so on are... but it's a thought...
By teh way, Mike, nice site, Bical and Raf pics are gorgeous.