Once we experience a few overnight frosts, the Yellowjacket activity will wane considerably (or stop altogether). Social wasp nests are not re-used from year to year, and at the end of the season, the colony's wasps die out except for a handful that overwinter elsewhere. Wasp spray can be used to kill workers coming and going from a nest if it can be directed into the nest entrance, but between not knowing where it is and the defensive behavior of the wasps, that's clearly not a great option in this situation. Unfortunately, the only recourse is to just avoid the area, if possible, for a few more weeks until the workers are dead. If you wanted to try looking for the nest with as little risk of stings as possible, you can do it while the insects are still chilled in the early morning and less likely to be flying.

Miri