ooops ... I forgot to mention the wine bottle(s) !
Depending on the planned menu for the midday break, I usually have one Chassagne-Montrachet or Pouilly-Fuiss? 75cl bottle.
Add a Pachenrec half-bottle, if there is any foie gras sandwich for Entr?es ...

Dehydration is too serious a risk, not to prepare seriously against it !