Whenever I travel with technology of any kind, I always find myself carrying a nest of handy cables and adapters. Clearly, when travelling light and with hand luggage, smaller and lighter are the two key words.
So here is my latest technical addition in that quest for light-weight and compact.
Raspberry Pi Retractable RJ-45 Ethernet Cable
Despite most hotels offering wifi solutions. I still find myself plugging in occasionally. This is exactly what you need.