If one of the toddler's will be under 3 when you go, you can try for an AKV value 1BR although it would be a tight fit as value rooms are "value" because of smaller size than other
DVC rooms. Owners of a resort such as AKV can book beginning 11 months from date of arrival; owners from other DVC resorts can book there beginning 7 months from date of arrival. The value rooms tend to go quickly once the 11 month window opens except 1BRs are usually open for a while and once in a while even at 7 months out. There is no 1BR as inexpensive as the AKV value at 139 points a week in Sep (less if going for a shorter time). The one with the next lowest cost is BWV standard view at 154 points per week. Like AKV value it has issues of filling quickly after the 11 month window opens. However, 1BRs are usually open well beyond the time when studios and 2BRs fill and there is some chance you could even get a BWV standard view 1BR in Sep at 7 months out. OKW 1BRs, which are huge, are 157 points per week in Sep. and AKV standard view 1BRs, which at Kidani are particulary large and have 2 bathrooms, come in at 162 points per week
If you really want to assure getting the value 1BR, you should be looking for an owner to rent from now (meaning start looking immediately) so you can have a chance to get the reservation made in October at 11 months out from date of arrival. You could check the rent/trade board on this site for an owner that may have AKV points to rent and contact that owner. You could also go through a rental broker like David's, dvcrequest.com. Do likewise if looking for BWV standard view 1BR. Otherwise if you instead can do the OKW or AKV standard view 1BR, you have plenty of time as those will definitely be open at 7 months out for Sep. but you should still set up the rental deal before the 7 month window opens, i.e., it is best not to wait beyond the 7 month window to try to reserve.
If you are considering a studio, the ones at VGF (standard view), Poly (standard view), VWL, and BWV (any view), are all less costly than a AKV value 1BR and have an extra bed in the form of a murphy bed that pulls down from a large cabinet below the TV (BWV is currently undergoing that additon which will be done this year). Those VGF and Poly rooms are quite large. if you want a VGF studio, you need to find an owner who will rent quickly because VGF stduos disappear at the 11 month reservation window many times of the year. However, Poly, BWV pool/garden view, and VWL should be open erven at 7 months out for Sep.