Henrietta Lovell of rareteacompany.com upsets the orthodoxy to which most of us cling by insisting that good tea does not need to be made with boiling water. Only cheap industrial tea, as available, for example, in WW2, needs to be.
Mrs Beeton (1907 edition) insists on boiling water, but says nothing about warming the pot.
Another (more credible) challenge to orthodoxy is to add warm instead of cold milk. Some say that the flavour is better preserved that way.
The English will never admit that you can reheat tea, but you can. It becomes a degree more soothing: less, not more, bitter. As soon as you realise that you can microwave the remains of a pot, the only reason to use teabags disappears.
If Hitler had seen this film, Operation Sea Lion would surely have been revived.