I am unfamiliar Camelbaks' offering but looking at their packs they seem kind of small and we are getting into October...which can be stinking cold at night, below freezing above 10,000'.
A few things...
You should consider an electrolyte replacement...about 2 liters should do ya for this trip. My preference is Cytomax. This means carry an extra bottle of some sort.
Does the pack have enough room for warmies that would get you through the night, if you really screw up and get stuck up high. Never leave home without enough warmies to get you through the night safely.
The only time I carry more than 2 L of water is on Trail Camp to Trail Camp RT. I carry 4 L because that gives me a margin of error most times on this trip. I have used 3 to 5 L doing this or Guitar Lake to Trail Camp...the five on a day near freezing all day.
How much water you need is dependent on your body. There are no firm or fast rules. You just do not want dehydrate.
