The purple pitchers should be fine where you are in the winter. It may be too cold for the VFTS, they may need the fridge when it comes close to first frost.

They should be ok outside. You're not far from where the VFTs grow in the wild. The purple pitcher can withstand colder temps. Put them up next to the house in an area protected from wind. Don't let them dry out and don't keep them wet, just damp when they start dieing back. They may die back completely to the ground but don't worry. When they come back next spring begin watering normally.

There's a variety of approaches to deal with dormancy. Tommy's is one. I have taken VFT pots and put them in the butter keeper of the fridge door. I used to have an apartment with an attic with broad windows and take all the VFT's & Sarracenias up there, so they would respond to the temperature and photoperiod cues. I have since moved and the last two winters these plants were toted to a co-worker's garage. Or you can do as one very experienced hobbyist (Wildbill), who lives in connecticut. He heabily mulches his plants with pine needles. It depends where you live, whether it is in the mountains or more coastal.

Dormancy is more a process than ane event. It actually begins in late June when the photoperiod begins to decrease. It doesn't become noticeable until late summer / fall. Conversely, the new growing season actually begins in late December as the photperiod begins to lengthen. That isn't noticeable until late winter / spring.