We have done nearly everything you mention to winter cows. We swath graze a mixture of Oats/Barley/Fall Rye and also have used Triticale. We also bale graze hay, greenfeed, straw, etc. This winter we actually wound up feeding barley to save our feed pile through a pretty chilly 5 months. We have also grazed corn. We have done this/do this with cows, bulls, backgrounder calves, etc.
I think you can probably bale graze without fences more easily than swath grazing. The problem with not controlling/limiting access in any of these systems is that the cattle will cherry pick all the good stuff (grain) and leave the straw. This can create a problem if the weather gets cold for too long and the cattle only have straw left in the rows. This is not such a big problem with hay.
We don't bale graze on native, but on tame it has boosted our production tremendously (some areas went from 500# DM/Acre to over 6000#).
We are a long ways North of you and there is a lot of winter corn gazing going on here. Some guys have their costs under $1 per day with corn.
Not sure how often you are willing to move fence, but our experience shows that even every 10 days and you can get a good cleanup.
A bunch of research shows the losses from shredding on the ground approaches 15% of the feed value for mixed hay and our bale grazing experience shows much less waste than that.
If you bale/swath graze the same area every year then you need to watch your phosphate levels as they will increase and you will need to bump up the Ca in your mineral.
Our swath grazing averages about 160 AUGD per acre most years with no inputs other than seed, and swathing. Our costs usually run between $0.37 and $0.55 per day (includes all equipment, labour, land rent at local rates and input costs). Bale grazing is better in a big snow winter and also for relocating nutrients to the tops of the knolls.
I like the swath grazing and the triticale has worked well for us, as I have pulled as many as 4 crops off a single seeding. Also with the inclusion of fall rye and a bit of volunteer barley, we will typically gain another 30AUGD before we cultivate to reseed to swath grazing. This likely wouldn't work so well if you are cropping and rotating things through, thus needing to seed earlier than a continual swath grazing situation.
If you are going to use corn, look for fairly short heat units but a little longer than your area supports (so the corn doesn't totally ripen), corn that matures cobs down (so they don't get wet and rot) and dent/semi-dent varieties seem to be preferred up here. Most of the corn is in prior to the 20th of May.
The hotter the diet the more you need to move fence, since you don't want to bounce the rumen microbes and lead to acidosis.
We are in Twp 48 just south of Lloyd, and I have friends at Meadow Lake that are growing/grazing corn quite successfully so I suspect it would work down there too.
FWIW.
