Someone else is sure to ask: When you said it fermented in your chest freezer at 67 degrees, was that the ambient temperature inside the chest freezer, or the temperature of the wort that the yeast were fermenting?
Wort temperatures can get up to 10 degrees higher than ambient, so your wort (and the yeast in it) could have been as high as 77 degrees F, which is a bit outside the recommended range for that yeast: 64 to 70 degrees F. And if that was the case, the yeast may have finished, or nearly so, fermenting your wort.