Our first big family trip was ten days long, with 4 generations, from two 3 yr olds and a four yr old to the 89 yr old matriarch. It was the first trip for the youngest and oldest and one in the middle! There were a few "oops" moments, but very few and nothing serious. We opted for offsite, paying well under $200/night for a spacious, well-equipped 5 bedroom/5 bathroom house.
Besides the amazing value, it meant we pulled up to our door every night, not into a huge parking lot. We carried sleeping toddlers straight into our front door, and to their beds, not through long corridors. The kids splashed about in our private pool while we put breakfast together, which was often eaten poolside. We were together, with a big common space where we could relax and go over the next day's place, even soak in our private spa,while the kids slept. We also had ample room in our spacious foyer to roll in and recharge my mother's ECV every night.
We toured long hours, but with the kids napped in strollers and we made lots of time for the relaxing attractions. The children played in every water fountain and play space in every park. Although we swore it was not necessary to keep the pack together, we wound up that way most of the time, purely by choice. It was actually very convenient because it wasn't forced. We were our own baby swap system for everything from attractions to shopping.
The biggest thing that worked for us was the rule of too. Every adult was responsible for themselves as well as for a watchful eye on everyone in the party to make sure no one got too hot, too hungry, too tired or overstimulated. We agreed to try to head off those conditions at all cost. We would chose to laugh, rather than snap, if something didn't go our way.
In ten days, we had exactly two meltdowns and they were over quickly. One was the result of our youngest DGD leaving her treasured Little Mermaid lunch bag on a monorail, which was tracked down by her dutiful father. Our youngest DGS wanted to push his stroller rather than ride, when his mom said no. He was quickly, quietly scooped up and set straight by his mother!!!! A crowded park is no place for a three year reckless driver.
We alternated Park and water park days, and even did a
MVMCP. Magical memories to last a lifetime. I hope your trip will be every bit as good for your family.