Is there another way of keeping a NG Impatiens by overwintering, ...... besides cuttings?

Is it possible to let it die down just before the frost in it's patio container, and then keep it inside in a dark,dry storage area where the temp. is cool but never cold?

I am trying to help someone with this ,so I would appreciate any suggestions!

All her condo windows face north , and so cuttings may not be workable.

Thanks,

Caro BC