I am amazed that you have kept them alive since 2011! It just goes to show that if you know what you are doing you can indeed keep the pitcher plants going. Give yourself a pat on the back for your accomplishment! It's amazing how many people even with all the information on the internet manage to kill them. We treat them like weeds nowadays ha, ha.
You could put them on the shelf in the pond as long as the pond is filled with rainwater. Just tap water will bump them off. If it is a pond where the water running into it is rainwater then they will be fine.
I can't remember if you took any Darlingtonia cobra plants but they will be fine as well and can be kept outside all winter along with the hardy sarracenia.
I've stopped tearing my hair out about our plot supervisor. You know it took them five years to talk to us again. They mentioned something along the line of 'it being nice to talk again after all that happened'. I kept my thoughts to myself (dammit) and I just gave a weird answer about 'living for the now and not the then' which I'm not quite sure they absorbed fully.
I'm off now to make some replica tombstones for Halloween! Woohoo oh joy ha, ha.