Hi I left everything to the last minute but MYA will give you a list of hotels and also on the Highgate website they list some, my only problem was that not all included parking and I did not want to leave my car on a normal street in London, anyway I then decided to book a travelodge just because of the parking etc. I went to one near Heathrow its on the M4 and is so simple for me coming from Wales, its nothing special but tbh I was not bothered, there was a shop and a burger king so I knew my husband could at least get something to eat.
Only problem was that in the morning when I left for the hospital the traffic was quite bad and although the sat nav originally said 34 minutes to arrive it actually took about 1hr 15 mins so bear that in mind.
Good luck xx