Festooning, as in the photos, is more an escape from heat than crowding. The hive needs some type of upper vent/entrance.
The festooning bees are making room so that there is more room between bees, it is one way of cooling the hive, the bees on the bottom board that are busy fanning are another way of cooling the hive. Super might be necessary but my experience says they are more in need of air conditioning.
When the hive gets crowded and hot inside then you'll see bearding which looks like a swarm hanging on the outside of the hive. Then they need room and venting and probably a split as they may have decided to swarm so a check for queen cells is always warranted when genuine bearding is present.