I feel your pain, OP
I used to have a very elaborate tea "station" at my office desk, complete with my own Adagio kettle (with configurable settings!), a cha-koboshi for discarded water, a tea thermometer, and a huge collection of tea wares.
Then last spring my office went mobile
and everything I use has to fit inside a tiny locker. There wasn't room any more for my beloved tea things! (Not to mention my work-related stuff...
Well, needs must. Nowadays I have a small tea set consisting of a small canister filled with Adagio's Yunnan Black tea, a thermos (to be filled with nearly-boiling water), a small gaiwan for brewing the tea, and a yunomi to decant the tea into. The whole thing fits on a jolly little red-lacquered tray. I chose Yunnan Black because it's a marvellously forgiving black tea so even if I under- or over-brew, or the temperature of the water isn't quite
right, it's still really good to drink. And using a gaiwan means that I can make cup after cup, each one fresh and hot.
I miss the days when I prepared gyokuro for my fellow workers at the end of the day, but... you've got to work with what you've got!
Anyway, I do think the gaiwan solution is a great one for the office. The tea is always fresh and hot because you drink each small cup immediately after you brew it. Heck, if you're really minimalist, you can even drink your tea directly out of the gaiwan