I didn't use formula, but having friends and family who did and traveling with them, this is what I think would work best. Use the Playtex disposable nursers this way you only have to bring 1 'bottle' frame. Fill the little baggies with powder in the room before you go to the parks for the day. The regular Playtex baggies you would need to use twist ties for, but they make others with a Ziploc type top, I think mine were Medela. Then just bring a few bottles of water, or buy them as needed in the parks, and when your baby is ready for a feeding, just slip the baggie with the formula powder over the bottle frame, pour in your water, and shake it up! This way at the end of the day you aren't carting back tons of bottles to be cleaned. I would toss in a few nipples so that you don't have to worry about cleaning them perfectly after each feeding-you can rinse them or clean them as best as you can in the parks, then do a better cleaning once you get back to the resort.
Also, not sure about every baby care center, but the one in AK has an Avent steam sterilizer, so maybe you could stop in there a couple of times and throw the nipples in since you probably won't be able to clean them as well in the parks/resort as you can at home. We used this to clean my daughter's pacifiers a few times since I'd normally run them through the dishwasher at home so I didn't feel they were as clean with my handwashing in the resort sink.