Personally, I think those storage length vs moisture charts are OK, except for fines, which seem to be a problem to most everyone in this 2009 season. If you did a 100% good job of keeping them from the center of the bin, then you're OK. If you were successful at that, please advise me of how. If, like most spreaders allow, the fines dropped to the center of the bin (not heavy enough to be flung out), you may have some heating (natural fermentation process) of the cores. Of course, you can remove the cores early, though you may incur some heavy f.m. discounts on those relative few bus. However, taking that discount may save the bin in the long run.

Personally, I'd be running the fans almost continuously, and certainly run them on the sub-zero days. Corn can be lowered below freezing temps, but in my experience it tends to warm itself again rather quickly due to air migration up thru the corn from the drying floor, assuming you have one. I've seen this utilizing our "bin temp probe cables".