"I just took a quick look at the one hive that we lost this winter. There is a lot of stores in there (at least 10 frames between top and bottom box) . If remove the reducer, is it possible that the other hives will rob this one to keep themselves going till spring finally arrives. The days are starting to warm up and they are starting to fly, but I don't feel it is warm enough yet that I want to open up the inner cover to check their stores. I was hoping they would get the feed they need from the dead out."
leaving a deadout open just invites unwanted pests and it is not good practice to let the bees rob out, as perry mentioned. you can utilize these frames either by placing them in hives (as perry said) or if temps not warm enough to messing with swapping frames out......... place them over the inner covers of other hives that may need feed, and cover with an extra box. the bees will utilize the honey.