You need to keep your carbohydrate intake high for the whole week before the ride, while gradualy reducing your training. This will cause your body to store extra carbohydrate (glycogen).
On the morning of the ride, get a high carbohydrate meal in at least 1 hour before the ride (2 hours if its going to be an intense start). As soon as you are riding eat more carbohydrate foods and energy drink. Given the length of the ride, something sold like jam sandwiches or energy bars will go down well. Also don't make your energy drinks too strong (keep them at 7% or less).
Aim to drink lots during the ride as this will affect your ability to ride the distance at speed.