When you guys do a run like this, what do you do about food and drink?

I assume you take a small pack with you, but what do you carry? How much food?
Do you use a drinking bladder?
Do you replenish at Nant Peris and Ogwen? Do you have a support team, or just leave a car/stash?

I did this as a walk last month, we all drank more water than we could have carried, and really relied on having a good scoff at the two meeting points to get us through.

Does your training mean you can do with less food and drink?