The north end of Cayuga froze to somewhere below Union Springs (no open water was visible from the Union Springs launch). Around Aurora was open water. I haven't been to Ithaca in a few months, but heard that there wasn't as much ice at the south end of the lake as there was at the north end.
I'm sure Seneca had lots of open water. I heard a story that guys at the Seneca Army Depot (or maybe it was Sampson) used to tell soldiers from more southern areas that they could put Seneca Lake water in their radiatiors because it would not freeze.
Unfortunately the large areas of shallow water at the ends of the lakes, where the birds can feed, are often frozen.