Do you have a big family? Because when I travel with my family, I hire a 7-seater car, which is ideal for family trips. It has plenty of space and fits all the luggage well. So if you are still interested in this option, you can find info here https://rental24.co.uk/uk/group/7-seater

You can try uber number one on the list https://thecitizenseven.com/article/3-apps-you-will-definitely-need-in-london

Definitely try large Ubers and Bolts – they compete with each other and run promotions every week

As for me, the best choice will be the AtoB airport taxi service: https://atobtransfer.com/.

It will easily get you to your destination. And it is very comfortable, especially for families, you can add baby seats or choose a bigger car.

A family cab service will alleviate your travel woes and allow you to relax and enjoy the ride. Trains and other public transportation are both inconvenient and uncomfortable when carrying a lot of luggage. Pre-booking cabs for a family is a better option than juggling train schedules and organizing your travel accordingly. I used http://www.simber.co.uk as a private tour chauffeur service and I am satisfied with their service because they have a big vans and limos for travelling with kids and family.