Earlier quoted context omitted.
I've encountered the same issue (high plastic bottle waste along with high cost). Short of boiling your own water outdoors to avoid polluting the indoor air, it's challenging to find a source for bulk distilled water.
Boiling your water indoors will humidify the air.
I live in an area with very hard water (around 300ppm), and the evaporated minerals are very visible in the air (and it leaves a white residue on the surrounding area).