The tiny bits of ice you buy in the bags (or make in trays) melts so quickly and is ridiculously expensive, IMO. So for a recent camping trip I froze entire gallon jugs (former milk jugs.) We still had ice (and cold drinks) on the 3rd day. As they melted, we had clean, COLD water to drink or make coffee with, despite the 95 degree heat every day.
We do this when going to the beach, also. Plastic water bottles, or rinsed soda bottles which take up much less room work well and stay frozen all day.
For any size, fill about halfway first, then add more water after the first part is frozen. Leave a little room at the top for expansion, and wait until they are frozen solid to put the lids back on.