Hello, Helen!
This is a great question! Especially if this is going to be your first nighttime race event. My first night race during the 2011 Disney Wine & Dine Half Marathon was not a very magical experience for the reasons you mention above - I didn't know how to manage my day. I learned from that experience and made sure to implement a better plan when I ran at night again in the 2012 Twilight Zone Tower of Terror™ 10-Miler.
Here's what I did that made the difference. These tips may work for you too!
-Adjusted my sleeping patterns several nights before the race.
-Did a few night runs, even if they were short. My first night race was also my first night run, ever! Not a good idea.
-Managed my nutrition and hydration levels better by making sure I carried water and a snack bag of pretzels with me. My first night race I got so caught up in hitting the parks before the race and visiting with friends I didn't eat right or hydrate nearly enough throughout the day.
-Speaking of theme parks, if you're wanting a park day on race day, go in the morning and only do a few key attractions. The average guest walks about 12 miles during a full day in the parks, that's more than you have to run! Save your heavy park time for after the race.
-Hydrate early, hydrate often, both during the day and during the race.
-For great nutritional advice, select the highlighted link to see what the official
runDisney Nutritionist, Tara Gidus has to say on fueling for nighttime runs. She offers excellent tips for fueling that will help you complete this race into the 5th dimension successfully.
Don't forget to stop by and ask any additional questions you may have, Helen! October will be here before you know it!
Have fun running 'till you drop!
Faith