You may be a bit surprised when it comes to feeling like you're in England. We were in London just shy of two weeks and I think we spoke to 2 or 3 native Brits. Almost everyone in the hotel and service industry is eastern European. Nothing wrong with that. London is a very cosmopolitan city. Just don't expect a lot of British accents.
And if you travel by subway (The Tube), be somewhere else during rush hour in the evening. The trains are seriously packed, although that's probably nothing new to a New Yorker.