It's a pretty small photo, but I think it's Miscanthus sinensis. I can't tell what cultivar without photos of the plant and especially a closeup of a blade. It's perennial, and not invasive in your zone.

She got the IDs she needed. Thanks folks!

I have a mystery NOID that I bought as Merrillii but the foliage isn't on the list. It has never bloomed so that won't work either. I will photograph it tomorrow and humbly ask for help ; ) Thanks for the link Aurora

There may be a "rule" about this as there are many rules on Houzz but I think I would hang it like drapes, it should be a bit wider than the artwork so i wouldn't shorten it. Who knows, later, you may want to hang multiple pieces from it or in a wider space and you'll regret having cut it shorter. Really nice look, enjoy!