Where are you over-wintering them? Is the overwintering location warm and enclosed or open to the cold/freezing? If it enclosed and warm you may need to water from time to time.
Just curious but did you over-winter because you had no where to plant them? If you just wanted a more mature clump then most over-wintered container plants/grasses are wintered outdoors if their hardy to the area. I'm confused. I should think they would have been better off planted. Jest my 2 cents :)

Vera

Mike,
If they're in the ground in Zone 5, then don't worry about them drying out. If they're in pots outdoors then you might need to water once in a while. Pots indoors, even if they're in an unheated shed or cold garage, definitely can dry out and you should keep an eye on them.

If you have potted Little Bluestem indoors, I would think about gradually moving it outdoors and finally letting it freeze. I think LBS might not grow well next spring if it doesn't get enough cold weather this winter. Plants from cold winter climates typically need cold weather, and they have some minimum duration of cold that they require, in order to thrive the next spring.

I am primarily concerned about them being TOO damp. They are not drying out at all.
These are overwintering in an unheated building as I was under the impression that the new plants should not FREEZE, correct? Here in N Indiana they would freeze solid--

I am overwintering bec I plan to plug these into the landscape later...Not too confusing, I hope...?

I don't think freezing would harm the plants. I regularly allow potted plants to freeze and they regularly come right back in the spring. Little Bluestem may require some time spent at very cool or freezing temps in order to simulate winter. Without winter, the plants won't be ready for spring. I suspect that it is possible to give the plants enough cold without actually freezing them, but I'd make sure that they are very close to freezing at least part of the winter.