[...] sometimes you end up finding only large bottles of some sort of alcohol, 1.5 L or more [...]
Yup. And not obvious what to do (ex refill an "official" fuel bottle, strap on top of the other stuff; do you discard excess fuel, how, etc.).
The more info I get, the more I think that, in Ladakh, canister will be the default option (available in several towns due to the popularity of trekking), in addition to a small emergency alcohol stove and hand sanitizer. Or perhaps learning the best way to cook on yak dung which apparently can fuel a backpacking wood stove
