Hotels in Oxford/London

https://maps.app.goo.gl/rhBhBqLXKJ6PnJyC7

Premier inn near Hayes and Harlington station

While I have no specific hotel recommendations,

• was in Oxford recently and there are roadworks going around the train station area,
  which may affect your ability to get to any hotel. Also, I don't think there are that many
  hotels in close proximity to the train station, so maybe find a hotel close to the rental
  car dropoff and then taxi/bus to train station upon departure?

• for London, if you are there for more than just an overnight before the flight, and are
  open to spending a bit more for the Elizabeth Line (or Heathrow Express) to LHR, that
  opens up staying in central London near Paddington, as it is under 30 mins to the
  Terminal 2/3 stop.

If it's only overnight, the Premier Inn is great, also there are plenty of hotels along Bath
Road north of the airport that are reasonably priced and a short bus ride to the airport
bus stop.

There is an Aerotel in Terminal 3. It's a budget hotel. I've never stayed there.

Less than a ten minute walk, via underground passage is a Hilton Garden Inn next to Terminal 2. I've stayed here numerous times.

There are also a few hotels near T4 and a Sofitel near T5.

I was in Oxford just a couple of months ago and stayed at the Marriott Courtyard there, which was about an 8 to 9 minute walk from the train station. And yes there was construction but it didn’t hinder my walk at all. I liked that location because it gave me easy access to most of the sites and was in a relatively secluded part of the city center so there wasn’t too much in the way of noise. Unfortunately, I don’t know what the price is, because I used points. But I can’t imagine it would be that much above $200. A lot depends on the dates you’re looking for, too.

In London’s Paddington neighborhood where you can access the Elizabeth Line to LHR is a Holiday Inn and a few blocks away #63 Bayswater where I’ve stayed off and on for years.

https://hotel63.co.uk/

Also consider staying above the Pride of Paddington Pub. Right across the street from Paddington station. Reasonable price and charming place.

We just did a very similar trip in May. Our hotel in Oxford was with points, and it was just ok so I don't recommend it.

But for the structure of your trip, I would suggest doing 6 nights in London in the beginning and at the end from Oxford, either turning in your your car in Oxford or keeping it for the drive to LHR and turning it in there. The night before your trip, either take the express bus to LHR or drive yourself and stay at a hotel at LHR. It makes it so easy to walk to the terminal and not have such a stressful, early morning.

For a stay in London, consider South Kensington, where you have easy access to the Piccadilly line direct to the airport - Premier Inn Kensington/ Earl's Court - it's also easy to get to central London on the Tube. But if you have to be at LHR at 06:30, then the Premier Inn right in the airport the night before.