Hi Barbie!
A fellow Carolina Girl!
September is a wonderful time of year to visit! The crowds are low, the weather is beautiful and you can experience
MIckey's-Not-So-Scary-Halloween-Party!
I can understand your dilemma. You know your grandson the best and your intuition will tell you if you feel he is old enough to come to Disney and still allow you and your granddaughter to enjoy your time.
I have been bringing my children since they were toddlers and my daughter had a great time at two years old. She was able to last all day at the parks and she didn't mind being on-the-go, in the heat or off of her normal schedule. Many two-year-olds do wonderful at Walt Disney World and have a great time!
However, some two-year-olds thrive on routine and don't do well if they aren't able to nap, eat and play on a regular schedule. Some two-year-olds also don't do well with crowds or loud noises. If this is the case with your grandson, you may consider bringing him back in a few years when he can appreciate it a little more.
However, if you decide to bring him, as an added bonus, you don't have to pay for admission for children under the age of three and he can also share meals with you at the dining locations, therefore it will not be an added expense.
No matter what you decide, I know you and your granddaughter will have a magical time at Walt Disney World!
Magically,
Stacy