If you want to keep them going over the winter cut them back enough to get them inside. You'll need some grow lights. A window doesn't provide enough light and there's not enough hours of daylight during the winter anyway. Cut back on watering. Even during the summer I keep my passies on the dry side but I would mist the foliage to try and prevent spider mites and other nasty critters. You can also allow those varieties to go dormant in your garage or some other cold room. I think it's just a bit too cold outside in your zone. If you allow them to go dormant cut the foliage way back and water just enough to keep the roots from drying out. This is what works for me. You'll start collecting more passies. There's so many beautiful varieties and they can be so different from each other.
Karyn

Just wanted to remind people that instead of going in the trash, the results of pruning can always be sent to others as unrooted cuttings (can they be sent in padded envelopes if one is careful?). And one need not expect a trade--some of us already have too much(!), others have nothing to trade. Hopefully there are a few people out there who will settle for postage/envelope or box and a big thank-you.

Personally I'm not looking for anything at the moment, but I also have nothing big enough for cuttings--next year. I just wanted to point out that what we literally throw in the trash might be greatly appreciated by others.

And all we have to do is mention it here (there's also the exchanges section). Perhaps someone could start a thread on available unrooted cuttings and people could add on from there...

It could be a nice resource. Seeds can be saved for later exchanges; prunings must be dealt with immediately. And seriously, how many potential cuttings ended up in the landfill last time you pruned?