OK, we are from Australia. In 2017 we went to Orlando with our 19 month old, it was over 23 hours on a plane and she loved it. We stayed for 3 weeks and she is now 3 and still talks about it. I would NEVER change that trip, it was so amazing for all of us.
In 3 months we are heading back this time with her now being 3 and we will also have our 10 month old with us. Same long flight, same September heat, we don't care. It is going to be fantastic!
We are staying for 4 weeks this time, there is so much to do and then some.
With kids you don't want to plan too much, so sometimes you might miss out on something but who cares as long as your LO is happy, you'll have a great time.
If you only have 2 weeks then go with that but if you can take a bit longer do it, it's easier on the kids not to have to travel again too soon after arriving and plus like I said you'll need the time to be able to do a lot of stuff (or just relax and do "nothing")
If you have any questions please ask.