At, say, 0400? That's what the previous poster was seeking.
Somewhere he might get one at that time is a truck stop, the modern version of a transport cafe.
Possibly so. Though many of those roadside cafes open later, e.g. the Super Sausage near Towcester is 7:30am weekdays, 7am weekends (not sure why earlier on a weekend).
In MK itself, short of asking a Premier Inn, the only place I know of that will do a full English early enough to be before work is Morrisons. Definitely not 4am! I suspect those truckers might go for McD's, though that doesn't I think start breakfast until 6.
Compare to Hamburg Maashchen marshalling yard , or Zurich TMD - the former serving the best ever Shnitzel in the world , with home made onion sauce , the latter serving pints of strong beer with every meal ("we only allow one drink per meal" in response to our incredulous questions......)
Many things about DB, the ICE aside, are like BR was about 20-30 years earlier, so I can believe the alcohol policy being similar to the way you hear it was in the 80s and early 90s. For one example I went to the Oktoberfest in about 2010. We were staying in Salzburg (cheaper than Munich) and on the train back the guard was very obviously drunk, clearly having spent his break in a Bierzelt. Other than turning a blind eye to smoking he was operating the train fine, but he was all over the place and you could smell it on him.
But talking of meals, I've often mentioned that the "breakfast, dinner, tea" vs "breakfast, lunch, dinner" thing isn't just north and south having different words but more because a dinner is a sit down hot meal whenever you have it (unless it's breakfast), and in the north the mill owner would provide it at midday because you couldn't afford to have it at home, whereas in the farming south you'd have a sandwich in the fields and have the big meal in the evening after working the farm for the day. Germany as a whole was attached to this idea until fairly recently and still in some places is, noting that their evening meal is even called "Abendbrot" - evening bread. As the main meal is at lunchtime, a good quality, subsidised work canteen is an expectation.