Enlarged Adenoids, Allergies, Nasal Congestion, No Sleep Apnea, . Had Dental Surgery. Was Under Sedation. What Is The Solution?

My son had an xray to see if he had enlarged adenoids. Recently, he had dental surgery for cavities and was under sedation. The dentist said he was a mouth breather and his adenoids looked enlarged. He doesn't have sleep apnea, but he does have chronic allergies with nasal congestion. His xray came back as having moderate adenoid and tonsils. He is 6 years old and was a premie. Will the ENTdoc suggest surgery? He sleeps normally. Sometimes, he coughs in bed at night, but doesn't awake, goes back to sleep. He doesn't stop breathing either. When he has a cold, sometimes it seems like he stops breathing for a couple of seconds. What do you usually advise? Thanks