Nah, proper milk (**) is part of the tea ceremony (cf "National Tea Day" ). As [you are] a Professional Tea Drinker I can't believe you're even entertaining the idea of the dried stuff . On single nighters I put some in a 175ml school milk bottle, freeze it, take it out of the freezer as I depart, wrap it in foil, then it's melted by next morning. Some goes in me porridge and some goes in me tea. On multiple days, either buy a pint last thing - it'll keep 'til morning, shove it in a stream or something (*) - or apparently I'm quite good at blagging some from pubs / cafes / random unsuspecting householders the evening before. I admit there aren't [m]any random householders on top of a very remote mountain.
Dried milk is probably good for use as emergency foot powder.
I hope Stu's not listening to all this sacrilege.
(*) in the unlikely event it's gone off overnight, well, at least you've got some yogurt for breakfast as a change
(**) "many non-dairy alternatives are available" of course