I only have one son. DH doesn't like Disney, and he's just fine with the two of us doing mini Orlando trips without him. We've done about five of these, and on three of the five actually met up with some other family. Two were just the two of us. These were really fun and hence the reason for five not one. // And I'm totally cool to with my guys doing things together without me. I think it's just terrific for them to have some quality one on one time with each other. // Do note that we pick a place everyone like and all go together on our major vacation each year.
I'd just be open and honest and talk to your wife and see how she feels. Just open up your heart to her and communicate with her. Tell her if it's true and it sounds like it is, that maybe it's a crazy idea and if it's something she's not in favor of and doesn't think is a good idea that you're OK with that and will skip it. Tell her it just sounded kind of fun and whimsical though and you wanted to get her thoughts/feelings, not just skip the idea if it's something that she'd be OK with. And say too that the last thing you would want to do in any way, shape, or form is hurt her feelings or your other daughters feelings if that's true and it sounds like it is. // If you're concerned about her giving you honest feedback tell her that too. Tell her you really and truly don't want her to say yes just to please you if in her heart of heats she doesn't like the idea. I'm guessing that's true too. // In any of this, though, let her know how you really feel. If any of the above is not what you feel don't say that.
Let us know how it goes. These are great things to talk to a spouse about. // I know earlier in our marriage I had this silly preconceived notion that all our travel should be all together as a family. But reality was the DH was really happier staying home when it was anything Orlando, but he was totally fine with our using some vacation budget money and going. Being able to stay home and that being OK was really a huge relief to him. And I was much happier just going there with DS who shared the same enthusiasm and enjoyed the same kind of pace I do in Orlando vs. bringing DH along and sort of being torn and trying to cater to him a bit and do things he'd like which by the way doesn't include theme parks. And when we finally just talked about it OMG, we were so much on the same page. // You're situation is different than that because you all like Orlando. But the talking to each other and sharing your feelings part is sort of the same thing.
Logic and feelings aren't the same and the sharing of feelings and listening to each other's feelings is what strengthens and enriches a marriage.