Travelling with CPAP

So far I've only travelled with my CPAP machine by car or train. Next month I'll be flying with it for the first time. The Canadian Air Transport Security Authority clearly states that distilled water for CPAP machines are allowed as carry-on and exempted from the 100ml restrictions.

Has anyone travelled by plane with distilled water for CPAP recently? What were the best ways to declare it, pack it, and process it? I would have a copy of my prescription with my name, of course.

I currently can only find distilled water in 2L bottles with handles at a pharmacy. Are there smaller bottles? Would they accept smaller containers hand-labelled as distilled water?

I can always go to the airport and ask directly, but getting experiences from actual travellers also helps...