Sorry, HTB I don't buy that. Any serviceman without the initiative and resourcefulness to get themselves somehow; bus/hitchhike/ mates car/ ask Mummy, to where they're needed within an agreed timescale, frankly, isn't likely to be of much use in defending our nation.
Similar argument re. Frost protection. Considering the billions of £'s of highly complex equipment we have, is keeping some plumbing from freezing really such a big ask?