Feeding syrup (adding moisture to the hive) is never a good idea in the winter. Good chance of giving them dysentery.
yeah, i was thinking up to October possibly. i'm using one now to see if they try to build so far all they do is walk around killing the few ants that get in. what would you think about using just the top box as hive insulation ? would it help the cluster maintain their heat ?
i'm just trying to stay ahead of the curve should they go into fall without proper reserves.