If you want to look at serviced apartments, I’ve had some excellent stays with these people. Kind of halfway house between hotels & someone’s flat: https://www.nativeplaces.com/

So I rented a place two years ago that is bigger than you need--slept 5. I rented through Booking.com but there was a leasing agency that ran it. It was called City Relay (formerly FG Properties). The one we stayed at was Chelsea Gunter Light House.

I liked the property, cleanliness, updated furnishings etc., all very good. One of the bedrooms was tiny but I knew that upfront. Keep an eye out on booking.com for City Relay. You could rent through booking.com. It looks like you could go directly through the leasing agency--but I haven't tried it myself.

https://cityrelay.com/stay/

We rented with One Fine Stay in Notting Hill and had a very good experience. They were responsive and the transaction worked very smoothly. Unfortunately "our" lovely one-bedroom apartment is no longer offered by them.

Hi Scootoir, what street was that one-bedroom Onefinestay flat on?

Artesian Road. It was a bit of a walk to the Underground but the neighborhood had lots of good restaurants. We met the son of our upstairs neighbor one day when he was visiting and they gave us a handwritten list of their favorites.

Just asking since we were letting a one-bedroom through Onefinestay, but it's not that one. We had people asking to rent it again, but it is now let long term.
It's in the same area, which we love.

It is a great area. We began using the bus system on that trip because the stops were more convenient than the tube. Pushed us out of our comfort zone with good results. Used the bus quite a bit more on the trip after that.