Hi. My son is 4mo and outgrowing his current diaper covers. I'd like to find some covers that will grow with him until he is using the toilet. He is 75th percentile for height, average for weight. My first child's height has been 50th percentile and she outgrew the one-size Fuzzi Bunz by age 2, even after replacing the elastics. So what's a good OS cover for tall/long babies that will last into toddlerhood?