We usually always eat at Disney late night when we do SW. It all depends on what SW's hours are when you go. Usually if they close at 7 pm, you should try to give yourself 1 hr or more to get out to the taxis (assuming this is your means of transportation) and back to the resort. If you are on the furthest WDW resorts (ie AKL), you might want to give yourself a little extra time.
We will also schedule a meal at DTD the night we go to SW. DTD is the closest point to SW, and it will also keep your taxi fare to a minimum. From DTD, you can always take Disney Transportation back to your resort. For conversations sake, you might want to try a 8:30 reservation if SW closes at 7. It sounds like a lot of time, but we've cut it too close too many times, even though SW is a half hour drive.
If you drive yourselves, the schedule is really up to you.