Nikitin hotels have mixer taps in this country as a rule. I say this as someone who used to travel the country and stayed in my fair share of depressingly familiar hotel rooms.
Check that out, Premier Inn, the biggest chain in the UK and look at the tour. Mixer taps on the sink, mixer taps on the bath. Furthermore I'm amazed you think people would care enough to carry one in a suitcase. I'm not intentionally trying to put a downer on it, well I guess I am but trying to do it nicely so those words are intended to soften this unsuccessfully I suspect: man that is a terribly founded idea based on a misconception that A. People care that much about taps and B. That the UK doesn't use them and people would care so much as presented in A as to carry an appliance around.