Dry girls

The girls (especially Norah) have had a rough time this winter with really dry dry skin. I'm not sure what to do. Not to be gross, but we've decided to bathe them every other day, instead of every day....but even that doesn't seem to help much. I've got the humidifier running constantly upstairs but I'm not sure that does enough. And then, we lather up the girls in baby oil twice a day. Still dry. Ideas?