I am in same boat. Family of 6. How many days you planning on spending at parks? We are going late August, staying on site for 7 days. With volcano Bay opening, it is possible we will do 3-4 days of parks minimum. Might throw seaworld or aquatica in there for a day. As I said earlier post, the unlimited explorer ticket is a good option for us.
Rather depends on how many. Days you want to go to the parks. At some point, makes sense to upgrade whatever's let you buy to an Annual Pass you can use next year some time.