Ren He wasn't in a hurry, so Steve didn't need to be either. Ren He had even specifically instructed not to let this matter affect the other's Hawaii vacation—after all, it was already quite embarrassing to disrupt someone's normal life…
Steve never felt like Ren He had anything to be embarrassed about! He returned to New York with his wife and kids and, in the dead of night, drove to a suburban house, cautiously surveying the surroundings before entering.
This was his safe house, where all the equipment he had ever used was stored in the basement. The house was registered under a name that had nothing to do with him, so even if this safe house was compromised, it wouldn't be a problem.
The CIA's work is primarily overseas, and they have no law enforcement authority in the United States. Setting up safe houses abroad is unregulated, but it's not the same domestically.
Steve had mostly worked in Europe before, but that didn't hinder his familiarity with his own country.
