a couple nights it was cold enough for all my water to freeze. some of those nights my water froze IN MY TENT, where it was (comparatively) warm.
it didn't have to happen more than once or twice before i decided it would be best to pour out the morning tea water into the pan and let it freeze there. it takes a little more fuel to heat your tea water from a block of ice, but there's a time savings of a couple of hours, which seems rather important when the thing you are waiting for is to put hot tea and hot oatmeal into you.
some nights it was warm enough that i knew my water wouldn't freeze solid overnight so i didn't pour it out, but in the morning when i poured it into the pan i got instant slushie.