Good advice!
If fermentation starts and finishes OK, when it is done, I would also plan to bulk age this wine and doing it for well over a year (which is a good thing, anyway).
Normally during bulk aging, one will add about 1/4 teaspoon of sulfate every three months. Based on that, you already have added enough sulfate for about 18 to 21 months of bulk aging. Of course a lot of what you added by mistake will have been used up during stirring and fermentation and will not be carried onto bulk aging.
If I were you, during bulk aging I would buy myself a good sulfate testing kit and test the wine every 3 months or so, rather than arbitrarily adding 1/4 teaspoon of sulfate. At some point the levels will equal out, so you don't want the wine to spoil.
This raises an interesting question for me - If fermentation does start and end properly, to stabilize, will MikeMary still need to add sulfites along with sorbate?
Maybe if they bulk age, they can get by with adding only the sorbate.