To me, this is an interesting question as to when to stop feeding. And I haven't really figured out the answer. I stopped feeding when water dropped below 55. They were still feeding, but how much of the food was being converted to body mass vs being poop out to increase nutrient load in pond? Were is that line of diminishing return, so to speak?
I don't know the answer but I kept feeding down to and including 50 degrees (assuming my thermometer is correct, which it is just a swimming pool thermometer so it may not be).
When my water first dropped to 50, it was still almost a month early from when I stopped last year. So I figured it would warm up again. It did some and the fish fed actively all through the period with the exception of a couple of very cold windy days. I fed up till Dec 8th this year. Fish were not only feeding well but also biting well and we cleaned over 400 BG along with several CC this fall, with about half of them caught when water temps were in the 50-55 degrees range.
My feeding reasoning was, as long as they were biting a baited hook good, they were actively feeding and hungry so I was going to keep up with the supplimental feeding (3# per acre AM MVP with a little Optimal BG mixed in).
Not saying what I did was right, just what I did.