I am a part-time master’s student who currently lives in a village north of London. I commute to London via King’s Cross, therefore my experience will only be useful to part-time students! It takes me half an hour to get to King’s Cross, 15 minutes to get to Holborn by tube, and then it’s a 10 minute leisurely walk to the Strand Campus. Therefore my commute is about an hour altogether, which is pretty much how long it takes to get from one place to another within London.
Part-time study translates to around 5 hours of in-class time per week, so I currently have to be on the Strand for 2 hours on Thursday and 2 hours on Friday. Other than that, I can study from home. King’s has absolutely fantastic online facilities so it is really easy to keep in touch with tutors and students. King’s also makes it easy to view course material online through Keats, the internal network for students and professors. I work in addition to studying, but my work is also flexible and allows me to work from home. The time I do need to go in to the office I try and make it coincide with the days I am in London for university. That said, I only travel to London 3-4 times a week maximum, which rarely exceeds £40 a week. Bearing in mind living outside London means everything else is cheap, £40 is not too bad in the grand scheme of things.
That said, my advice to you (especially if you are a part-time student with reduced work hours) is this: living outside the M25 and commuting to university is very manageable, therefore it is definitely something that should be considered. The campus is so central that it is close to all main stations such as Waterloo, London Bridge and King’s Cross St. Pancras. I enjoy the best of both worlds: the country living, walks and reading in the parks, while also being able to go to London when it’s time to work!