How difficult is it to leave and eat at a nearby restaurant

Not difficult at all

If you don't have a car, you'll need to Lyft. Lyft also has a built in service for Disney called Minnie Van, that comes equipped with car seats. If you're relying on buses to get you around, you can't go from resort to resort. You'll need to go to one of the parks and catch another bus from there. If you have your own car, none of this matters, and Jeffrey is right, it's not difficult at all.