Hello JAbbo87
Congratulations on making the commitment to run this January 9. The course is very flat, and very enjoyable.
Regarding the start, I was a first timer this last January 11, and I certainly did not arrive at 4 am for the 6 am start. I was staying at the BWI, and walked out of the lobby at 5 am. At that time there was a large traffic jam on the road running east-west behing EPCOT, and I began to walk behind EPCOT toward the start. As I headed east a very nice WDW bus driver pulled up, asked if I was headed to the start (yes!), and said to hop in. I gladly sat down and she went past the Swan, merged on the main road to the MK, then turned right into the EPCOT parking lot. She parked and disgorged her runners at about 5:30, and at that time many, many runners were similarly arriving and heading for the start. I followed all of them (it sort of felt like the "Night of the Living Dead," lots of people moving quickly and throwing shadows from the bank lights), and even with a port a potty stop I was in place in the starting corral by 5:45.
As I stood there, many people suddenly came towards the starting corrals from the OKW, jumped into their place, and were ready to run. I guessed these folks had gotten out of bed at 5 am at the latest, had stretched, etc. then had zipped over to the start. It was clear to me that they were the smart runners, and I was not. Live and learn.
So, I think your strategy is very sound, as I saw many others use it last January. Remember 26 miles is a long trek, and standing out in the cold for 2 hours isn't going to make it any easier. I'm like you, the longer I can sleep and the less I can stand before a race the better.
Good luck with your training, and be sure to bring cold weather outerware for the time you spend in the starting corrals. It may be warm, but it's more likely to me cold and damp at that hour.