Are these boots fully waterproof?

The upper is described as waterproof, so rain, slush and wet snow should stay out. Water can still enter over the top in deep drifts or through the cuff if you wade.

How warm are they in freezing weather?

The microfiber lining reflects body heat back to the foot, which keeps them warm on cold commutes and errands. They are not rated for extreme cold or long periods standing still outdoors.

Do they work on ice and packed snow?

The rubber outsole is built for winter surfaces and gives decent grip on packed snow and slush. On sheer ice, no rubber tread replaces traction aids.

How should I size them?

Winter boots are usually worn with thicker socks, so consider a little extra room over your normal shoe size. The soft lining takes up some volume.

Are they good for everyday wear or only deep snow?

They are aimed at everyday cold and wet weather: commuting, errands and shoveling. For deep backcountry snow or long hikes, a stiffer, more technical boot is the better pick.