We usually leave a bit after DS's bedtime. We aim to be on the road no later than 10:00 PM on Thursday night. We drive through the night, missing all the rush hour traffic down through DC. We usually do 4 hour shifts, stop for coffee, bathrooms, etc. When DS wakes in the morning, we stop for a good long breakfast, change of clothes, a nice walk. Then, we try to stay on the road until lunch. Lunch is a long picnic with another walk and playtime for DS. We easily make the NC/SC border before dinner.
We get back on the road by 9:00 the next morning, and make it just outside Daytona before dinner. Again, we try to stay on a 4-hour shift schedule, with a nice long break at lunch. From Daytona, it is an hour's drive to WDW!
For our DS, age 3 the last drive down, some htings we brought were: Crayola Wonder markers, magna doodle, color forms, small tray puzzles. These were all brand new, wrapped like presents. Every time he got bored with one, we'd take out a new "present" and start over. Worked so well, he only watched one movie on the TV/VCR we brought! BTW, Crayola Wonders are markers that only work on special paper, eliminating messes form the back seat. We bought the lap desk set. He used it for snacks too, not just his coloring. Crayons are a huge NO! Too melty! We also brought some old faves from home to keep him comfortable and happy. And plenty of snacks!
We camped on the way down, so our places to stop at night wouldn't be of much help to you. Sorry! Hope you have a great trip!