I took a 3 month old last year. We drove 1000 miles with 3 kids including the baby. We had a great time. The Orlando parks are very friendly to babies. You can “baby swap”.
This means you take the baby to the exit of the rides, which most times is air-conditioned. Some new rides even have special rooms for this purpose. Then your husband takes the kids on the ride. After they are done, they meet you and you get first priority on the next ride. YOu can take 3 people back on the swap so my 2 older kids got to ride everything twice with no extra waiting. ( Once with Dad, once with me) they loved it!
I loved it too because while they waited on line, I could rest , nurse , or change the baby without having to waste time. Also, having the stroller was a huge help. We carried a collapsible cooler with ALL our food and drinks. Then we didn’t have to wait in line or spend money on the food and it was always with us.
We carried the baby in the sling when she was fussy and some rides you can even take her right on in the sling. We never paid for parking. We parked at “boardwalk” Disney’s new shopping complex. From there you can take a boat to Epcot and MGM. I would recommend “Doing Disney Like A Pro”.
I got the book at my library and it had tons of great tips on avoiding crowds, prices, good things to do, etc. the Boardwalk tip came from there. Oh yea, the kids liked to get autographs from the characters. We picked up a cheap notebook at a drugstore. The autograph books in the park are $5. It goes without saying , don’t buy anything in the park if you can avoid it. You can get Disney stuff at Walmart or anywhere in Orlando. We had a great time and barely spent a cent besides our tickets and hotel.