I had a few extra MS Morning Light and a few MS Purpurascens that I put in a few large decorative pots thinking I would have some nice winter interest on the patio. I want these to survive for a few years.

I started reading that zones in containers are different than zones in the ground.

From what I am reading, I shouldn't leave these outside. I didn't think of that. I've read that in zone 5 territory, containers act maybe two zones higher (zone 7).

Anyone have any thoughts regarding ornamental grasses planted in containers above ground and overwintering? THX!