We are also a family of 5, and while you have a chance, I would really consider staying at WL and/or AKL. We love both and would love to be able to stay again. We would do AKL every time, but our youngest turns three this month so we have to bump up to the other resorts. You will be able to stay at all the monorail resorts after your baby would turn three. Just my 2 cents.