I'm "JUST a farmer-cattleman"...
I run my own herd of C/c and direct market my steers at finish (a little over 100 head total), and then I also operate a custom grazing operation, which this year operated with two separate herds (approximately 300 head of custom per year total). Yes, alot of the relatively few C/c operators that remain up here (most of the land here has been converted into corn/bean rowcropping) do run their C/c herds on their cornstalks during the winter... or at least for the first part of the winter after corn harvest, and then usually are feeding them alongside as well, usually some rounds, or stacks, plus a little grain.
I have gone "all grass fed", and have converted all of my farmland, which I was operating as 100% row-crop (corn and beans) into MIG grazing, or as hay for winter feeding. And I'm pretty much maxing out/optimizing my production for the grazing during the growing season, for the most part. That leaves me without any "cornstalk crop residues" to run the cattle on, though I would LOVE to have that option. I have "non-livestock neighbors" who do row crops, including cornstalks, but for the most part they've not even begun the mental migration into regenerative farming, they have no fences, and they're not too receptive to putting livestock (back) on their land.... YET! (ALL of the land in this area, 75 years ago, would have had cattle running on the fields in the fall... I am hopeful however... and am working on that). They generally wouldn't want to have to deal with the livestock... some would object to fences, none have water access on THEIR land, etc. I have installed watering stations on MY land in such a way that it would be very easy to use them when grazing on THEIR land too though... gotta have a plan as this movement evolves!
The custom grazing operation allows me the flexibility to manage for optimal grass benefit, and to "kick them off of my land", when I still have alot of grass remaining behind them. If I were running that many of my own cattle, I'd have to "keep them" through periods that I DON'T have to now... and with that many animals, I'd be "overstocked", because I couldn't get them removed from the land when I still had several months of grass left as "winter stockpile" remaining behind them... which is what I am able to put my own herd on right now, after the ground has frozen, and the snows have come, and the grass had gone into winter dormancy. THAT STRATEGY helps me to grow more grass during the growing season.
On the last graze across with the approximately 300 head of custom cattle, I had beautiful quality grass that was literally hip high on alot of my pastures... and I was leaving behind them grass that was still knee deep. The first of them left in early October, the last of them left on Oct. 22. The grass didn't grow much in tonnage at all after that graze (too late in the year, already freezing at night, sunlight not strong enough anymore, etc.), though the ground wasn't frozen yet, it WAS still alive, was NOT dormant, and it did continue to "recover" after their last pass across (say Sept. 1-late October, we expect hard "killing frost" here normally anytime after Sept. 15, but the pasture grasses don't "frost kill" really) and after they left (plant continues to push energy into it's top growth to recover from the grazing "injury"... improving its "quality", but not necessarily its "quantity" much). I turned my own herd of about 100 into those pastures (where it had been carrying those 300 head) on Dec. 1, after the ground was frozen, and after we had received about a foot of snow cover... and THAT is the winter stockpile that they're grazing right now.
If I didn't have those custom cattle as a part of my operation, I wouldn't have that winter stockpile right now.