We have a couple feeders but our winter birds are pretty boring: a couple types of sparrows, house finches, Oregon juncos, and magpies. This winter that's it. We don't even have the collared doves that we've had in past winters. A half dozen quail have wandered by a couple times but most of the time they're somewhere else.
I hear from the quail experts a covey with less than six or so has no chance to make it through the winter.
If a few barn owls or bobcat finds them a covey of 20 wont make it through.