Park at the TTC and take the resort monorail to the Contemporary and eat at Chef Mickey's. After dinner, walk to MK (a relatively short, leisurely stroll), and take the boat to the Grand Floridian. Check out the GF and the Polynesian next to it, and watch the fireworks from one of the resorts. Then walk or monorail back to the TTC to pick up your car.
All things "Disney" on a non park day.
Note that some of these could be changed depending upon where you're staying, what time you're arriving, and how your kids could handle all of this.