TJ in answer to your question, the BOW is right at 1 acre, average depth of 13', steep sides with very little shallow water. Little vegetation.
I think you'll have a much less chance of winter kill with a pond like that vs. a shallow weedy pond. Don't panic you may just come out just fine. One fish doesn't mean squat. I had a big perch die just before ice up probably of old age.
There is a possibility the jet stream trough and ridge could position itself farther east, and we could have a later winter and spring like last year. Totally opposite of our cold snap.