[Tilted Irish Kilt]

ApplegateRanch :" How long, and how, can the other bag be saved? Some are beginning to sprout in the bag.
I COULD plant them in the Fall, if they’ll keep."

Honestly I am unsure if they will keep for 4-5 months since you have already soaked them all.
I would cull those that haven't yet sprouted from the rest , and refrigerate them , especially if you have a spare fridge, or cool place in the garage.
Regardless, they will still need ventilation and air exposure , or else they will rot. Cold will stunt the growth of the non-sprouted.
I've not tried to keep onions for that long , as most of mine are used within a couple months
Another option is to barter with a neighbor who has a garden, or a crop of which you have a shortage , and can trade with each other .
I would put non-sprouts in the sun for a few days to dry them out before putting them in the fridge.

[ApplegateRanch]

No, I only soaked the bag I planted. I planned on staggering the planting by a couple of weeks, to facilitate harvest, so didn’t soak the remaining bag.

However, there is a spare “beer fridge” downstairs I can use to keep the non-sprouters. Thanks