60f is a winter night time temp where I am. Occasionally it gets to 50f. Summer is 5 months of 90-110.
I wouldn't be too concerned. If you really think they need more water, make their food a 24hr soaked runny porridge. Grain soaks it's own volume of water. Pellets and crumble soak almost...
Where is here and where was there?
There is a dramatic difference in water consumption between summer and winter where I live. Subtropical climate.
In summer the 17 of them will drink nearly all of a 3 litre waterer each day. In winter that will last a week.