Funny you should mention hotel/travel kettles, as a travel kettle IMO is too small (1 cup - 300-400ml?) and a standard 1.7ltr domestic kettle is slightly too large. But they make a 1ltr kettle for the hotel/hospitality industry which is perfect for the job. You can get them from catering suppliers online, I have one fitted with a European Shuko plug for my European travels, but is easily sorted should I need it for the truck
Edit: this is the one I have nisbets.co.uk/caterlite-hot … ttle/cl186
You can get em in stainless as well
nisbets.co.uk/caterlite-hotel-kettle/cd275