I have an electric kettle on the kitchen counter at home that is ye olde basic "boil water" kettle, because I am of British descent, and TEA DAMMIT. But at work, I have a rather better kettle where I can tell it "keep warm at X temperature" and it'll do that for an hour. So I boil the water, make tea in the kettle (it's glass, has a mesh basket inside) and have enough tea for the day -
about 1.5 L. And then at the end of the week, I scrub the kettle down.