Hi Shaun!
If it's the Graco Quattro Tour Duo Stroller, you may be able to navigate well with both in the same stroller. If you're referring to bringing 2 separate strollers, leave one.
If you're staying at a resort, and you can fit in your budget, I always recommend stroller rental over bringing your own. Rates do change periodically, but as of this writing (Feb 16th, 2010), double strollers are $31 per day or $27 per day if you get the multi-day pass.
It seems like much, but it saves all the headaches of lugging your own from resort-to bus-to park-to bus-to resort. The bus gets cramped, there's never really a good place to put the stroller, and breaking it down was always a problem for me.
Also, I didn't have to worry about that couple hundred dollar stroller leaving a parking area while inside a restaurant or on a ride.
I say the double stroller, which worked well with my 6 and 2 year old. Although my 6 year old technically could walk all day, they will get tired on you (all the excitement always got to my 6 year old princess. After a few hours, it was beauty nap time-smile).
But you might have a better system than I had, and breaking down the stroller/lugging it, may never be an issue for you..
Just something to keep in mind.
Best Regards!