Packing for London

I leave this Sunday, two weeks in London and Stratford-upon-Avon, my
first trip out of the country. Those of my acquaintance who have
travelled are shaking their heads over my packing list, wincing at my
two checked bags (one's really quite small, just a tote bag), clucking
their tongues at my three pairs of shoes. But most especially, they say,
my long, black trench coat must stay behind, it's far too bulky and heavy.

Well, it is bulky, and heavy, that's rather the point. But not bring my
London Fog to London? That hardly seems right or proper. However, from a
practical standpoint, my only real counter-argument is that I might need
it; sure, it's nice enough now, but arctic cold and bitter rain might
roll in at any time, and then my light leather jacket would be pitifully
inadequate.

Have I got a leg to stand on? Or will I end up much happier if I depart
sans coat?