Just FYI, pumping exclusively tends to be quite difficult, so I feel that I have to warn you that your plans are going to set you up for quite a challenge at a time when you are going to be very tired and hormonal anyway.
Your body depends on skin-to-skin stimulation to start up and effectively maintain the production process, and the mechanical pressure of the pump isn't nearly as effective. As a general rule, a baby can extract 3X the amount of milk as a pump can in the same amount of time. Most people who do exclusive pumping for convenience reasons (as opposed to medical necessity) give up on it fairly quickly, because it's just exhausting. Getting your supply up and going using only a pump usually requires hooking yourself up to it no less often than every 90 minutes for the first month or so, whereas if you both nurse AND pump, pumping 3X daily will usually maintain enough add'l supply to allow you to get out and about without baby quite often after the first four weeks. (It takes that long to get your supply up and steady, and once you do, for the next 2 months or so after that, you will need to either nurse or pump no less often than about once every four hours, or you will become engorged and very uncomfortable.)
I pumped extensively with both my kids because I travel for work, and I have overactive letdown, so I had to "pre-pump" a few times daily for the first few months to prevent them gagging on too much milk. (Also there are nutrition issues with foremilk and hindmilk, but I'll let you look that part up if you're curious.) I'm good at pumping, but I still don't do it in situations where I don't have to, because it's a PITA. I certainly wouldn't do it at WDW unless the baby were not with me.
Also, just FYI, though freshly expressed milk generally does keep for several hours at room temperature as previously mentioned, room temperature should be understood as no more than about 78F. Excessive heat WILL spoil it very quickly. Leaving a bottle exposed to Florida summer heat would speed up spoilage quite a lot. IME (and it's considerable, because of the business travel), that kind of heat will spoil EBM in something around 90 minutes.
Just to be sure that I answer your original question, there are outlets in the baby station nursing rooms in the parks, so it is possible to pump there with no problems.