Yes, Disney does offer land and sea packages varying in lengths depending on what you're looking for. The more popular ones are either a 3-night land package followed by a 4-night cruise or a 4-night land package followed by a 3-night cruise. But they do offer other options.
We are in our early 60's and loved our Disney cruise. Not real crazy about the food in the main dining room - found it good, but not as good as others.
But Disney has a wonderful private island and their shows are among the best in the industry.
They have adult-only areas on the ship as well as an adult-only pool, so you can escape the kids. Plus, they have an adult-only beach on their private island, which is very nice.
Besides the food, the only thing we weren't crazy about was the price. As you've found, it is quite expensive. Personally, for the money, because of our age and what we like, we found Celebrity to be a much better experience for us as we're foodies and the food on Celebrity is outstanding. But of course, Celebrity, like Holland America, attracts an older crowd, so they are considerably more sedate than Disney. If you're looking for a happy medium between the two, you might want to consider Princess. It really depends on what you're looking for, your budget, and your lifestyle. Best to talk with your agent, preferably a Cruise Specialist, who can help you find the perfect cruise for you.