My condolences on the death of your step-dad.

The Hilton Garden Inn by Hatton Cross does have a functional restaurant - they can cook food and have a typical chain hotel menu - and a reasonable bar (we have done the FT post-flight-sim debrief there several times). I have eaten there a few times, it was fine.

If you want to get out of the hotel, I do see that The Green Man is not far away but I haven't been there.

The Pheasant, north of Heathrow, does do good food and is a reasonable place to drink. They have a drinking/bar food side and a table service restaurant side which I'm sure serves the same drinks as the pub. Food quality is quite reasonable while service can be a bit slow.