When my oldest started in on his trying tantrum times (which for him was at eighteen months), we found that he did better with plenty of rest (He has always needed his sleep. He kept on with afternoon naps straight through kindergarten!) and plenty of routine. I found little pictures online of the things we did each day and arranged them on the fridge with magnets and he could see what was coming based on what we had already done.
So if I had opted to take him to WDW at that age, I think I would have tried to stick with those things.
I think we would have arranged our stay completely around his normal nap/eating schedule if possible, with just little short trips to the parks. At that young an age they have no expectations about what they will do when they get there, so I'd go for whatever had us waiting the least amount of time and I'd bring little books or whatnot to keep him occupied during any waits we did have.
I think we would have rented a car, to allow us more freedom and a private transportation experience. (In other words, if he only lasted until he got in the car, that would be okay.) Plus I think it would have been more familiar for him.
And I would have tried to limit my expectations. I would expect to have to work through a few tantrums in the parks and I would expect to spend more time at the resort than I ever did before. I might not even try to go into a park every day.
I think if you want to go, and you are willing to work your trip around your toddler, then it may go better than you are currently expecting. But I also think it's absolutely fine if you want to wait a bit and try then.
Also, and I think this is the absolutely most important thing I learned over the years.....don't let the people around you make you feel added stress or anxiety. A vast number of the people in the parks have either had young children themselves earlier in their lives or they still do have young children. And no matter what they may say, or how they act, or what they incorrectly remember, their children had tantrums at some point. Their children didn't listen at some point. Their child's favorite word was "NO!!!" at some point.
And for those who do not currently and/or have never had children, well they still
were children themselves at one point and I am sure their own parents could tell tales about them.
I found, with my oldest, that I allows the extremely judgmental nature of people on the
internet to put me into a place of near panic when I was in out in actual real-life public with my son because I was convinced that nearly anything we did would bother someone. And I hated the thought of bothering someone. Years of parenting, plus maturity as I got older, plus more experience with the ways people act online made me realize that not only was I making myself sick with worry, but I was making my son nervous, too. And I also realized that yes, someone probably would always find fault with something we did, because some people find fault with
everything. And that's their issue, not mine. So now, not only do I try to just enjoy time with my kids in public, but I also try to smile and offer words of encouragement when I see parents & kids struggling on an outing. I know how it was and I want them to know there's no reason for them to feel embarrassed or anxious about their child's choice of location in which to stop behaving their best.
It happens to us all.
I hope that whenever you choose to go, you have a wonderful time, and that you will look back and focus on the times in which you all were enjoying yourself, and let any of the melt-downs or moments of toddler/preschooler/etc. misbehavior fall away from your memories of the trip.
) my mom insisted what an amazing time the kid will have with her grand parents and I. That same grandma gave me a framed park map of every single place where my DD was in timeout after the trip and apologized lol. 
