The planter is about 6"x2' and has 5 plants in it (which I bought in 4" pots last spring). I hope to return them (or cuttings?) to the same planter outside next spring. Would it be better to separate them and plant them separately to keep in a sunny window, and replant next year or bring the whole thing in and leave them in the planter all winter?
I've never done cuttings before -- would they be about 4"-pot sized next spring if I took cuttings now? Or should I take cuttings next spring?

I tried to store last season's geraniums in the basement, unwatered and upside down with the soil shaken off, but they didn't make it. Not sure why.

Thank you for your advice :)