Crispy cold fried chicken James Beard rhapsodized about cold fried chicken, and I agree with him: not as good as fresh, but still the best thing at the picnic. Of course, if you pull the chicken out of the fryer, encase it in tupperware, and refrigerate it overnight, you'll end up with a soggy mess. Beard suggests allowing the chicken to cool at room temperature on a wire grille before refrigerating, to keep it from getting soggy.

I can confirm that this works decently well at preventing sogginess, but after refrigerating overnight, the coating is at best firm, nowhere near as crispy as it originally was. (This makes sense, of course: osmosis does not want you to have a dry coating on a moist drumstick.) How can I defy the laws of nature to achieve a durably crispy coating?
There’s a food processing trick, where producers use dextrin to keep the coating crisp for hours. You simply replace some of the flour (around 20%) in your recipe with dextrin and you’re good to go.

As the other answer mentions, multiple layers also helps creating a thick barrier to slow down moisture seeping into the coating. You can use dextrin in both layers.

Once you’ve adapted your recipe to use dextrin, frying followed by rapid cooling should give you a good result.