I cut the seed pods stems back to about 2' when they get heavy enough that they cause the stem to droop sideways. I am in PNW zone 8 and leave the plant in the ground over winter with no problem. If you are in a zone where crocosmias are not hardy, I would think overwintering in a garage would be fine. Not sure how often you'd need to water them, perhaps monthly? I've never garage-wintered anything. If it can't make it through my relatively mild winters, I don't grow it.
