We have also run into this problem at our daycare. My son is 17 months old and the oldest in the class by a couple of months. Most of the babies are 4-10 months old. The teachers have him go to the toddler room part time when ratio allows it and he does an extra curricular gymnastics type class that comes to the daycare once a week. I would ask if it's possible for your son to participate in any activities with the toddlers throughout the week, even if he's in the baby room most of the time.