Do i need PG solution in the summer?

i live down the shore and i keep my humidor in the den. i don't use a/c. i just leave the windows open. my humidor is never in direct sunlight. right now the temp in there is 78 degrees and the humidity is 75%. i haven't needed to add any solution since may/june when the ambient humidity started to go up. and no, beetles are not an issue.

so, is there any point in the solution or just wait till cold air comes back and dries everything up again?

You need beads. They will absorb moisture if it gets too dry and release it if it gets to humid. The key is constancy. You need to keep the environment inside the humidor stable. Humidity fluctuations will ruin your cigars faster than being too dry or too wet.