
I'm afraid coverage is a little hard to come by, but this is the Youtube stream from Radio Le Mans. They've forgotten more about endurance racing than I've ever known.
Stream Part 2
Stream Part 3 (Goes live about 6am Sunday)
Here's some other resources to help you out.
Live timings
Spotter's guide to the cars
Start and finish are on Quest (no I don't know what channel that is either), and I'll update this if I find any onboard streams.
Cars to keep an eye on:
#8 Toyota - LMP1 - The one all the media are concentrating on because Fernando Alonso is one of the drivers. Hope they don't find yet another way to lose it.
#11 BR1 - LMP1 - Jensen Button co-driving. This team's other car took off at Spa just over a month ago.
#31 Oreca - LMP2 - I'm not sure I'd want former F1 terror Crashtor Maldonado as a co-driver.
#32 Ligier - LMP2 - For all the fuss about Alonso, this one's got Juan Pablo Montoya onboard, and he's already won the Monaco GP and Indy 500. An outright win is unlikely but would give him the triple crown.
#92 Porsche 911 - GTE Pro - Fan's favourite, the Pink Pig.
Onboard streams:
#7 Toyota
#8 Toyota
Ford GTs
Alpine LMP2s
Rebellion LMP1s
1st retirement:
#4 Bykolles (Stuffed into the barriers)
Another:
#17 BR1 (Backed hard into barriers, then terminal engine damage limping to pits)
( , Sat 16 Jun 2018, 12:48, Reply)

Eurosport deleted my details, so seems like I've been given another 7-day free trial (I was actually quite happy to pay a few pennies for the race, but this was a nice surprise). Might be worth a try. Or less cheekily, if you've never subscribed to them, Eurosport have a 7-day free trial going on.
( , Sat 16 Jun 2018, 13:27, Reply)

and now I'm subscribed.
But honestly, I'll have the sound down and Radio Le Mans playing.
( , Sat 16 Jun 2018, 13:33, Reply)

Eurosport have a sort of endearing hopelessness to their commentary (it's a bit like test cricket's commentary in that) but at the end of the day it's not the best.
( , Sat 16 Jun 2018, 13:42, Reply)

All the marks leaving, there'll surely be a replacement now?
Toyota will no doubt break down at the finish line.
( , Sat 16 Jun 2018, 13:42, Reply)

The 2020 regulations were outlined for the first time yesterday.
And if Toyota manage to win it, my money would be on them doing it with #7 car.
( , Sat 16 Jun 2018, 13:46, Reply)

Except they're still rooted in prototypes, without the requirement to build any for the road. It's closer in concept to the DPI format in the US, where manufacturers build prototypes with clear styling cues from the road cars.
( , Sat 16 Jun 2018, 16:56, Reply)

Five years in the wilderness for Le Mans then while manufacturers turn the race into a parade for their flagship models, instead of their engineering prowess.
( , Sat 16 Jun 2018, 16:57, Reply)