We leave our pool open during the winter down here and run the pump when we have a cold snap and to circulate some overnight (minimal). Love the variable speed pump, btw! The SW chlorine generator doesn't work when the water gets below ~57 deg, so I dosed pool with bleach once this winter, I think. I run our Polaris once a week, on average, to suck up the leaves. I really don't feel like I put much effort into it over the winter. Just ran the complete test battery this afternoon (son is starting to get anxious to get in).
CYA: Not tested (solar cover is on to help warm the water)
CH: Not tested (vinyl liner)
All in all, I'm very happy with how it fared this winter!
Added some salt, some bleach, a little borax (need more), acid to counter ph rise due to the borax, and a little baking soda to bring the TA up a bit. Need to head to the store for supplies (NOT the pool store, tho )