By that point almost everyone will have been exposed anyway no matter what quarantine measures we take. At this point we're just trying to slow the spread, but essential activities have to continue (food, transportation, utilities, healthcare, infrastructure, military, emergency services, etc) and so everyone involved in those is going to act as transmission vectors. Once the vast majority of people have been exposed, any further widespread quarantine measures will become moot.

The airline industry is going to be crippled though, and might still be operating at limited capacity in October.