I wouldn’t worry too much about it. A honey bee swarm is usually between 5,000 and 30,000 bees. They generally land in a clump on a tree branch while looking for a new home. Sometimes they end up on the ground. Once they find a new home they will fly off.
Swarms are the time when honey bees are most docile (they are docile in general), as they have no hive to protect and they just want to find a new home!
On the next warm day I bet they’ll fly off. If you’re in Portland this will probably be today!