I used normal 2 liter glas bottles upside down in tins and small crocks, pros are normal drinking from crocks and automatic refilling, downside is cleaning and freezing.
I'm back to crocks, about 1liter, in winter I put electric heating pads under them. 3-5W are good for -10°C, if needed I can increase the power.
Since my rabbits drink close to nothing most of the year (90% green food) I change water about weekly.
Well, I can't say that's ok for all rabbits, or even most, since mine seem to be quite sturdy local farm meat mutts that don't care the least about things like coccidosis and stuff.