If you're flying carryon-only, your only option for traveling with alcohol is to fill your 3-1-1 bag (1 quart bag, 1 per traveler) with little single-serve bottles. We travel carryon-only ourselves, and DH and I have totally done this -- put our liquid/gel toiletries together in DH's 3-1-1 bag, and stuffed mine with enough booze to make ourselves little nightcaps in our hotel room. As long as each bottle is 3 oz. or less, it's no problem. I usually toss the 3-1-1 bag in my "personal item" for travel, so there's less risk of it getting smooshed somewhere along the way, but I'm sure it would be safe inside your carryon luggage as well (you might want to double-bag it after passing through security, just in case anything leaks). If you're traveling with kids, so much the better: they're each entitled to a 3-1-1 bag, too, and you can make use of their allotment -- put your toiletries in their 3-1-1 bag(s), and use your own for the grown-up beverages.
If 3-1-1 bags won't hold enough for what you have (or rather, your companion has) in mind, you can also, of course, buy/order a big bottle after you get to WDW. If you opt to order online and have it delivered to your hotel, e.g., as part of a grocery order (Amazon Prime Now, Publix Grocery Delivery), make sure you're familiar with the relevant policies, as some will require the purchaser to be there to present I.D. when the delivery person arrives.
[Photo borrowed from online at snowbrains.com]:
