Ashley, I'd guess you might save on a hour or three of time by staying in Windsor versus staying in London and then traveling out to Windsor the next day. Because you are arriving at 11pm, double check that your transport to your destination that first night is actually operating that late. You will need to grab your luggage and clear passport control. Hard to say how long that will take, but since it will be late at night I'd guess you'll be clear by midnight or so. But, you should add in more time. Your flight might be delayed. There might be a very long queue at passport control. You never know. If it looks like you will need transport at Heathrow after the buses and the Tube and the Heathrow Express stop running for the night, your alternatives get more expensive. You can take a taxi. Or, you can reserve a car and a driver who will meet you at Heathrow. I did the latter last year and it was just under 40 pounds to my London hotel. (There's also the advantage of being delivered to your destination's doorstep, rather than walking around past midnight trying to find it from a Tube or a bus stop.) If I had to do it myself, I'd take a cab from Heathrow to Windsor. It's only a few miles west. The fare should not be prohibitive. Oxford: Hotel prices are not amazingly lower than London: Many fewer hotels and a guaranteed stream of visitors to the colleges, etc. With a bit of research, you ought to be able to put together a self-guided Lewis tour. I wouldn't at all be surprised if the local tourist office hasn't already done that for you.