I've pruned back 3 plants of Pretty in Purple that were sharing a 10 inch pot, they were early fruiters, and the outermost branches were dying back, but there's new leaf growth on the lower stems, so I cut back to those.
I've previously overwintered, the 2nd year plant isn't as pretty in form as a newly grown one, but the fruit is earlier.
You will need to keep them in the house overwinter, preferably in the sunniest spot available.
Went to a chilli meet up at Upton Cheyney a few weeks back, Matt Simpson of Simpsons Seeds (good choice of chillies on his website), had a plant (Hot Lemon or similar) on display that was 6 - 7 years old.