Just over a year ago where I work changed (same company) from being 3 ish miles away to being over 10 miles away.
With the public transport being hilarious slow and convoluted, and no desire to drive in stop start traffic, I’ve remained commuting by bike though I have made changes both to the bike and clothing due to the distance, differences in type of area.
Which are for the bike I’ve fitted nearly puncture proof tyres since the good folks do like to liberally coat the parks/paths/roads with broken glass! I’ve also bought a better for the road bike light, which though not as powerful has a kinder beam shape and a remote so I can flick between high/dip without taking my hands of the bars.
For myself I did get a better coat and have started changing since though I wasn’t sweaty, it wasn’t hygiene to remain in the clothes, plus bike clothes are warmer/cooler etc.
Luckily from Heathrow up there is a long shared path that is traffic if not glass free that goes to and past work, it’s remarkably empty of others be that 6am or 10pm I rarely see anyone!
I started off and I have stuck to going via Bushy Park which is a park I love as it’s fairly gently managed. Linking up to Crane Park that follows the River Crane up to Hounslow Heath which is rather lovely it’s self.
Originally I did use some back roads to connect to the A30 and the shared path running north but was far too much rat running, so I use the main road which oddly is fine.
I have worked out a alternative from the A30 home via the amusingly named Donkey woods 
The decking is quite fun, in places it’s tilted which adds to the entertainment!
The route links follows the river crane until Feltham where I pick up some parks, and what not all the way home, it can be a rather wet muddy route but Has no busy roads and very few quiet roads under 2 miles out of 11 miles, my normal route is 5/12 split so close to half and half, that does have some busy roads but still low amounts.
The direct route which is same as the car is a mile shorter but fairly unpleasant roads though less glass strewn and though Heathrow!
All in all I like my new commute, it is longer takes at least a hr and I do need to change etc which adds faff, etc.