Well, we live in Massachusetts and have driven all the way to Disney several times. We are a family of 5 and playing the airline game got so ridiculous we decided to try the drive, and it wasn't so bad. The kids get excited and are always well behaved on the way (these are the same children who fight if we're driving 2 blocks for something else, but I digress

). I guess you never know until you try it once for yourself. For us, it became drive or don't go...so, we drive.
I can see your husband's point. If you are going all that way and will be that close to his family, it would seem wrong to not visit. I only wish I had family in Florida, it would be a good excuse to visit more often!