the treatment will not get all of the mites. since we are about to go into winter and you will have a definite break in the brood cycle where you live, you probably don't have to worry about it to much. you probably have a few that are coming in with bees, or have come out of brood....although you should have gotten most of those.
you are just about done getting into your hives for the winter? if you get in there again, PS wouldn't do any harm, but i wouldn't lose sleep over it.