Despite all that freezing and thawing, have there been any signs of life out there?

Yes. I had been somewhat concerned about the hanging feeder not emptying quickly, but this warmish day showed plenty of rabbit activity, and they must be quite hungry. I spotted a skinny rabbit in that dish one night when I looked out the kitchen window—they only come to the dish at night.
I am beginning to see black-capped chickadees, white-breasted nuthatches, cardinals, and mourning doves, but they are not going through the seed as they have in years past. Despite the weather, daffodils, snowdrops, and crocuses have broken ground, and the witch hazel flowers are unfurling when it gets above freezing.

These crocuses were moved from elsewhere, and I suspect the chipmunks of being their movers as they seem to be my most ambitious farmers. It would be more accurate to say that the big crocus was moved; the five satellite crocuses probably divided off the larger one that they are surrounding. The snowdrops are also peeking out, at least where there are breaks in the snow.

There is still some Rudbeckia seed for the chickadees out front, but I think those seed heads may be too close to the ground for the chickadees to feel safe.

The early spring bulbs are running slightly behind, but a few warm days should bring a lot of changes fast.