Winter Grasses

Even after such a deep heavy snow 3 weeks ago these dry grasses are still standing tall. Sometimes they get flattened and I have to take the hedge trimmer out and cut them down. They may last in the landscape until spring.
In the Extra:  The arbor vitae evergreens I planted in summer did not fair so well. The 4 feet of snow almost entirely covered them. Yet, I think they are not making it because they did not go into winter with enough water. They are alone in an exposed area too.
I was hoping they would grow into a privacy screen. Have to go to plan B or C
Already making garden plans for spring! Hope spring eternal in the Gardener's Soul.