Best time of year to divide Sarracenia and how

Simply stated, best time of year to divide Sarracenia and how. I am thinking the division process is similar to iris. I can break the clump in half with my hands or I can take an actual kitchen knife and slice down what appears to be a natural divide in the rhizomes with fall being the best time to do so. But then on the other hand, I am thinking maybe a spring division so that the plants would have all summer to get rooted in before they have to deal with freezing temps. Straighten out my thinking here please.

Another question. I would presume that Sarracenia, like iris, depends upon anything still green and healthy to feed the rhizome for more bloom and growth next spring. Unfortunately, Sarracenia is a tall plant much like an iris and high winds present in this area could possibly uproot them. The sphagnum/sand medium isn't exactly the most compact. Would it be safe to trim back the upper growth after the plants have totally browned to reduce the potential of wind damage getting them? If so, to what height should the spent growth be removed? 6"?