As an aside, the three year old may be too young to fully enjoy Disney; at that age the child's needs may impinge on your own enjoyment as well. I'm anticipating a Disney trip for my granddaughter but will probably wait until like age 5 or so. Fewer naps, more stamina, able to go on more rides, etc.
Agree with this. We waiting until my kids were 6 and 9, which worked out very well. Even then, the 6 year old struggled a bit with all the walking and long hours.