The issue I can see is that I need to do multiple actions.
Worst case: Pick up phone, unlock/pin, find and open app, wait for a moment, find option and press it. Best case: swipe on reminder, unlock, tap option.
The issue with the best case is that the 'cancel' action still has way less friction than the other. It is zero friction to ignore it but still 1-2 steps to do it.
The optimal case would be to be presented with the options on the lockscreen.
Perhaps you could schedule a minimum amount of notifications and display them at the same time?
Like at 7pm:
I am cleaning.
I am making dinner.
Etc. This way only one swipe would trigger the action (+pin). But it might be hard to get just right. But you see my point.
Anyway good luck. And for what it's worth, I'm still developing on an iPhone 4 as well :)