I confess, when going abroad in the past, I have taken some teabags, a plastic bag of instant coffee, a travel kettle and adaptor for the plug. Perhaps even some biscuits. Arriving at my hotel in Crete at 3a.m., there was nothing better than a cuppa and biccy while unpacking my nighty before crawling into bed.
When I used to go to Spain, it was impossible to find tea bags except in highly expensive packs of 5 and usually "speciality" teas.
On the train from NY to Ottawa, (1968), a 10 hour journey, with a £50 money limit for our 3 week holiday, my family and I certainly wished we had brought sandwiches and a thermos!
As for actual food, in the past I have found it difficult to get "local" cuisine in some destinations. MacDonalds are taking over the world. Thankfully, Crete seemed to be the exception and so long as I could avoid the almost ubiquitous olives (never could abide them) I enjoyed what was on offer.