Originally Posted by TNGabe
Cellar temp is probably too cool to see any activity.
I think what Gabe is getting at here is that you won't SEE activity at those temperatures. It does not necessarily mean everyone in there is dead.
I'm going to add a few thoughts:
The first set of dregs added to the wort may have fermented everything out. It is also conceivable that it happened overnight, without a krausen, or without you noticing. You shouldn't see any significant activity once it's fermented out.
I like to add cooled wort to bottles when I drink interesting sours, and slap a bottle airlock on them for storage. I have a Kriek De Ranke sitting like this right now. I didn't see any activity for weeks, and i was very close to dumping it, until I finally noticed a healthy an nasty looking krausen one day. I suspect it just took a very long time for the culture to grow up from the dregs.
There may be several factors impacting your situation: temperature, culture size, available sugars...
I'm sure you are you are on your way to some tasty sour beer! Good luck!