I wouldn't sweat it too much. I use as few clarifiers as possible (frequently, none) and actively avoid adding anything that is not 'native' to the wine, which is essentially grapes, yeast and maybe oak flavoring items (dust, cubes, spirals - which are all removed before bottling). That said, I do add k-meta at bottling time, but not as much as suggested (usually half or a little more of the kit's package, or ~1/16th teaspoon if it's not from a kit). If I am bulk aging it for a year, I will add it at least once during racking(s), but no batch gets more than three doses total.
Main thing I wanted to add, though, is that the problems that can arise from omitting sulfite will be gradual, over months, not overnight or a few days. If you notice some of the bottles you are aging starting to get worse instead of better (during periodic taste tests, of course), then drink it up and chalk it up to experience. But it won't suddenly go from great to horrible in one or two days' time, just because you omitted the sulfite - oxidization or contamination takes some time to have a dramatic effect on the bottle.