A few years back, in fact the last time my family and I stayed off site we stayed at the Spring Hill Suites Marriott Village which is located in the same complex as Fairfield. The pool was very nice for the children and it is located very close to Downtown Disney in the Lake Buena Vista and CRossroads Shopping area. They do offer a scheduled shuttlebus to and from the parks. There are many hotels in this area some a little nicer and some not so nice but the convenience is pretty good. For the cost of the hotels at the Marriott Village, which is usually less than $100 a night you can stay on site at one of the All Star Resorts at WDW and you can't beat the convenient bus system to and from the parks, the service and the pools are a lot more fun! During the time period you are going, it is difficult to get a reservation during this period but if you plan on going back try the All Stars instead for similar money! You don't have to buy a package when staying at a Disney Resort, you can simply ask the reservationist for a "room-only" reservation and buy your tickets elsewhere!
Have a great time! You will love Disney and definitely WANT to go back!