Well it seems like both choices are unheated? So keep it where there is the most sun. Water much less, about half as often as you would've.

They'll definately need light for about 8 hours a day. Cool conditions 45ðF to 55ðF and quite light on the watering. Air circulation helps too.
You just want to slow growth down to a snails pace until spring.

Cheers.

I'm in zone 7, and I had some basjoos, in pots, outside. Last fall, after the leaves dried from the cold, I took them out of their pots, shook most of the soil off the roots, cut all leaves except the top one off, and put them in a black plastic garbage bag. I have a finished basement room, where the only heat is from a wall-mounted electric heater. We only turn the heat on when we're using the room, because it's expensive to run. The room gets down to about 50ðF without the heat. I put the plants in that room, and put another garbage bag over the tops. They got no water, all winter. In fact, I didn't even go in the room, from November to April. On April 5th, I took them out, repotted them, and in about 10 days, they were growing fine again.

I'm in zone 7 too and have basjoos in both pots and the ground. I've left the ones in the ground for the past 5 years and had great success come spring. I cut them down to about a foot tall after the first frost. Then I cover them with leaves until spring. Over the winter the leaves settle and I loose the parts exposed to the elements, but come spring the bananas send up new leaves that poke through the pile of leaves. As for the basjoos in pots, I bring them into the unheated garage and remove all the leaves. I don't water them over the winter. Come spring they start sending out new leaves so I give them a little water and move them outside as it warms up. Here are some photos of my inground basjoos. The lowest temps so far are 31 degrees and I've not seen much leaf damage.
{{gwi:424116}}From Garden 2010

{{gwi:407711}}From Garden 2010