How to get there on tube from Kings Cross Station.
You can get the tube to Hatton Cross which will take less than an hour from the centre of town, you'll need to uber then final 10 mins of the journey.
2 options depending on your budget/ time to get there
tube from Kings X underground to Heathrow then a cab
more expensive but much quicker tube King X to Paddington the Heathrow Express to Heathrow & a cab from there
suggest Uber cabs from Heathrow, miles cheaper
Get an answer from The Stanwell Heathrow staff and past guests.