I know there's plenty of tech that's gone into creating these "hydration storage devices" but there remains a major problem with them. BOILING WATER! As you all know, boiling hot water (or nearly boiling) will distort plastic. Yeah, you can wait.. wait.. wait for it to cool off enough before you fill your plastic water bottles or packs or (like Patrick Haynes mentioned a Mt. Dew Bottle), but by then your nice bed of coals is in need of tending.
Usually I go with an old kettle, my Nalgene, an accordion thingy (2 ltr.) and an aluminum 4 qt. canteen. Sadly, the big ol' canteen is gone now and I've been searching for a replacement to my old Palco 4 qt. with no success.
Short of getting someone to custom weld one up for me, does anybody have any idea where to get a canteen larger than 2 qt. and not made out of plastic?

Clearly you have not been reading the ad copy for a lot of the "plastic" canteen makers. Both Nalgene and Platypus soft "plastic" canteens in all sizes are specifically designed to handle boiling water. I have, on many ocassions during the winter filled my platy or Nalgene soft canteen with boiling water and thrown it into my sleeping bag as a hot water bottle.

When I get home I often will boil my canteens to clean them.

The weight saving alone make using these alternatives to metal or hard sided plastic canteens worthwhile.

They come is sizes ranging from 1/2qt to 3 and 4 quart sizes, So finding one to fit your needs should be easy.

Boiling water does not distort a Gatorade bottle. I often heat spagetti sauce in the Nalgene bladder by setting it in boilng water.

Where I hike boiling often is below 200 degrees, but the PET beverage bottles do work.