If I was a camel, I could do that, not drink tea, that is. But I have to drink, sadly, tap water needs to be boiled anyway and buying bottled water would cost muuuch more than boiling what I already have.

Boiling lots of liquid at once would equal boiling smaller quantities more often if not for the energy losses due to the kettle getting warm and stuff. I know it's going to be really marginal and yet, small numbers sum up eventually.