Looking for room for one or two days a week

I usually work in London two days a week so looking for a room for one weekday night, which is most often Tuesday but sometimes other weekdays. Two or three weeks a year I need to work in London for longer and so ideally would also be able to use the room for 5/6 days from Saturday to Thursday on these weeks only. I can be flexible on this though. I am a professional with a family who lives in the north of England. I will only use the room in the evenings as I will be in the office all day.