My kids usually need a bunch of fillers to last them until summer. The babies/toddlers usually need a full next size. I learned the hard way to shop sales at December/January time because I know there will be barely anything when I need it.
I usually don't do well shopping a year advance, because I don't know how the kids will grow. Usually I buy things that can work for the season ahead or current.
But if your in Lakewood backstage by ladida is fabulous. Definitely worth the trip and they carry all seasons always.
The last time I was there I got a coat for my daughter for $60 was originally over $200, plus 2 pairs of Shabbos shoes for around $40/45 each. And lots of tees.