Back in the day (last century) I generally stopped fishing for river smallies in the fall, but this was more due to hunting season and trout and saltwater fishing.
These days I do a lot more cold weather fly rod bass fishing and typically fish until sometime around Thanksgiving, and sometimes into December. I usually resume fly fishing for river bass in March. I don't do much winter FFing for bass, but hit it sometimes. My best fly rod SMB in 2019 was a January fish and I had one of my best days on the Juniata fly fishing from shore when there was a dusting of snow on the ground. My best SMB last year was a tank of a fish that I caught while spin fishing for muskies. This massive fish, which I regret I didn't measure or photograph, crushed a huge spinnerbait near flooded shoreline bushes last December.
If there's ice in the river, I'd do something else.
