You need a large sized container for the grass.  The grass should be planted to the depth that it is in the existing container. You need plenty of soil for the grass root ball.  Do not put crushed cans or other material in the bottom of your pots as that would be detrimental to the plant. Karl Forester grass should be kept outside through the winter, it is a deciduous grass and needs its dormant period in order to do well. If you cannot bury the pot in the soil you need to find someway to insulate it so the roots do not freeze.  The foliage of the grasses make a good winter presentation. It should be cut back just prior to new shoot growth in early spring.

You can grow perennials that are hardy in your zone in containers and put them in the soil in the fall to winter over either in or out of their pots since they too need the dormant time.  Since the plants are not in the soil they will need you to attend to their water and basic nutrition needs. I am attaching a link on containers preparation.https://igrow.org/gardens/gardening/do-you-need-a-thriller-in-your-garden/

Thank you for your reply.  What might you suggest to insulate the pot through the winter? I don't have any kind of a flower bed deep enough to bury a pot. 

Thanks so much! 

Straw or straw bales arranged around the container would work or any heavy mulch can be used. Spink county appears to be mainly in Plant hardiness Zone 4a with   temperatures of -30 to -25 in the winter. If there is a nursery near by you might check to see how they insulate their plants in the winter.   I hope this helps.