The issue I was responding to is not the issue you addressed. I was responding to using a max of 5 x $10 coupons. You were referring to the fact that each purchase over $100, regardless of size, should only get a $10 coupon.
I can easily go to Cub, redeem 5 x $10, leave, come back later, rinse and repeat. Not that hard. Also, there are 2 Cubs in my town so just bop back and forth between the two a couple of times (not that far apart). I don't see why it wouldn't work with using way more than 5 x $10 coupons in one day, just perhaps a max of 5 per visit. Even if it were limited to 5 per day. We have more than 10 days before they expire on Dec 17, so one could easily use over $500 of them if they visited every day.
Why waste time when you can go to a store that will impose no limits and let you stack them?