Will your vacation be at a time that you can take advantage of the Magical Express feature? If so, here's an option for you. My family of 5 stayed at the Hawthorn Suites Orlando Airport location. They had a complimentary shuttle service from the airport and were located about 10 minutes away. The rooms are all suites, so that's a separate bedroom, full kitchen area and living room. In the morning, they had a complimentary breakfast with eggs and pancakes. You can arrange to take their shuttle back to the airport and get on the Disney Magical Express. I'm sure that many off site hotels do have transportation to WDW, but it would be to the specific parks and not an actual resort.
As for the Hyatt Orlando, that's really convenient, but they don't have rooms for 5 people (unless you have one that's under 3). They do offer a family plan, which is booking one room at full price and getting an adjoining room for 50% off. The rooms can be expensive though.
Tammi