We've done several split stays, but I honestly wouldn't do a split stay for a week. I won't split unless we're there for at least 10 days. IMHO its just too hectic with small kids, packing and unpacking. It is nice to have two different resorts but this last vacation we stayed the whole two weeks at YC and even the kids said they liked staying put rather than switching.
Of course in July (when we take the whole kit and kaboodle) we have to split our stay. THe Magical Gathering will be at WL (deluxe - but less expensive) and when the older kids and their families leave DH, me and the little ones will have to move over to GF or YC. We're going to put one of the younger kids in one of the other rooms when we do the Grand Gathering, since WL rooms only sleep 4.
Whatever you decide I'm sure you'll have a great time, but think it through because it is a little chaotic when your kids are young.