Those are good points. Perhaps an alternative is to have many multi-use small containers, like I have for hiking. Something's got to be better than always using one-time usage plastic bottles. Of course recycling them helps, but so few people do that.
I have a stainless water bottle (hydroflask; insulated) that I use myself for water and tea, but reusable = expensive = can't just give to people and not get back.
The energy and environmental cost of ~6-12 cases of water per year isn't really that big a deal. The extra fuel burned by carrying 5kg might be more than the cost of the water bottles.
