I use the 4 liter Sawyer bag system at base camp and quick disconnects to fill my Camelback and my brother's too.
Generally though, our drill goes like this: First day at base camp, while we're fresh, rested and setting everything up, we continuously filter and fill up about 10-12 gallons of water in collapsible 3-4 gallon containers so we have water for several days. The longer the hunt goes, the longer the walk to creek seems to be, so we get ahead of it as much as possible before we're tired and jammed for time.
We use these collapsible jugs from REI for our base camp water stash, they're cheap and light:
GSI Outdoors Folding Water Cube - 3.9 gal. - REI.com
Best,
John
JL