Jayne,
That IS a long day to be at Disney and not go to the parks. As I said, there is ice skating... you could explore all the resorts and take a long lovely lunch at one of the resort restaurants... does your son like arcades? The neighboring Val d'Europe looks nice, though I've never been there... if you are up for shopping... also what about going into Paris for the day, or even for a few hours?
Of course, if it were me, I'd buy the 3 day ticket... but I'm a dyed in the wool Disney fanatic!
I'm sure whatever you do you'll end up having a lovely time.
I might have more suggestions for you when I return from my trip on Feb. 2... is that before you leave?
Jody