I regrettably have to revise my one hive hanging in there. Was getting more and more concerned about them and the fact that I wasn't see any flying even on decent days. So I went into it today after work. All dead. It looks like they starved out surrounded by stores. small pockets of bees buried head in literally inches from capped honey. Disappointing to be sure. So at least I have some capped honey to feed my packages. 1 3lb package of Russians coming in a couple weeks and a package of Caucasians next month. With a cutout planned next weekend if the weather cooperates. Too bad it's probably too late to order an extra package :-D
From you location, the fact you are a Northern tier state which have suffered such severe cold weather, and you discription of what you found I would have to say what you found was a case of the bees being forced to maintain cluster for such a long period of time to a long cold period that the bees couldn't break cluster to transfer more stores into the center of the cluster and they starved because they couldn't or wouldn't move.
BTW, Caucasians are Russian Bees, just from around the Black Sea instead of in the northern Urals. Caucasians were the bees I found along the Turkish Black Sea Coast when I was there thanks to Uncle Sam.