I've gotten somewhat opposed to using bottled water for everyday drinking. Besides being expensive it's ridiculously wasteful of fuel (transporting it), petrochemicals (plastic bottles), etc. That industry just shouldn't exist on anything like its current scale. I do find the 0.5l bottles convenient at times and keep a bunch of them in my car and use them as needed, but at home I just drink the tap water which isn't bad where I am. If the tap water were worse I'd put in an RO system rather than drink bottled water all the time. I have a 1 gal jug on the kitchen table (I like room temperature water) which I keep full of tap water for drinking. Letting the water stand in the bottle for a few hours makes it taste a bit better. I seem to drink close to a gallon a day.

I have a bunch of 1 gal jugs of tap water stashed away and haven't been rotating them though I should. 6 months is probably way more frequent rotation than needed. Also, bottled water probably isn't sterilized like aqua-blox, so it too would need rotation almost as much as tap water. Finally, if SHTF, funky tap water that hasn't been rotated in years is probably still cleaner than water from a stream, so treating it with a camping filter should make it safe to drink.

Perhaps a reasonable plan involving aqua-tainers and tap water and rotation would be to fill a bunch of aqua-tainers and then use them as drinking dispensers, cycling through them and refilling them as they get emptied. A family would probably use several a week.

If I were to store bottled water I'd probably get it in those 2.5 gallon rectangular containers, less hassle than larger numbers of smaller bottles. But I worry about their leaking as the weather changes or if the containers are stacked.