I 2nd the thread that @momofboiler1 suggested. I feel for your situation. You’ll get great support in that thread.
We went through a variation of this w/my MIL in the early part of D24’s senior year of high school. MIL didn’t live overseas, but about a 1.5 drive from us. Refused repeatedly (despite DH & his sister’s multiple attempts to convince her) to deal with estate matters (she didn’t have a will, or power of attorney, or a healthcare directive) or to deal with any decisions related to one’s increasing health needs as one ages.
It all came to a head just when D24’s senior year started, about a week or 2 after MIL’s birthday, when MIL checked herself into the hospital for severe abdominal pain. To make a long story short, she had uterine cancer that she didn’t know about (she didn’t go to a gynecologist for 25 yr, no pelvic exams, nothing) and it had spread to surrounding tissue + ballooned the size of her uterus.
She died on Friday of Labor Day weekend that year. SIL lives a 6.5 hr drive away so we were the closest ones. DH did the 3 hr round trip drive there on almost a daily basis for 5 weeks. It wasn’t until about a week before she died that DH was finally about to get her to sign any estate documents and get a healthcare power of attorney set up.
In the years prior to her death, DH tried for AGES to convince his mom to sort through her mountain of belongings that she’d accrued over the years. She refused. When asked by her son if it bothered her that she was going to leave him and his sister with all of this work after she died, she said (~ 2 months before she died), “It won’t matter. I won’t have to deal with it because I’ll be dead!”
at the end of the day, H & I were the ones who dealt with all of her stuff. He & SIL decided what stuff they wanted to keep. She had about half of her garage full of clutter…all of that got thrown away and I was the one who dealt with all that. To put things into perspective, MIL saved literally every greeting card that anybody had ever sent her.
The weekend of her death was hell, thanks to an aunt & uncle that came into town and made things all about them. They decided to stay at MIL’s house so they wouldn’t have to pay for a hotel or campground fees (brought their camper van w/them). Brought the aunt’s cat w/them, too, and let the cat roam free in MIL’s house despite H & SIL saying not to, then claimed that 1 of MIL’s 2 cats “tried to kill” their cat. 
Actually slept in MIL’s bed. Complained about the amount of dust in MIL’s bedroom (MIL hadn’t actually been in the house for 5.5 wk at that point). Complained that H hadn’t stocked the fridge with food for them. Told us about how we should spend hordes of money fixing up the house to sell it (we didn’t, house got sold ‘as is’ to Open Door). Told us how ugly they thought H & SIL’s favorite pieces of MIL’s furniture were.
It was hell. On the aunt & uncle’s departure date, I stayed back to make sure that they actually left because they had a track record at that point of constantly delaying/postponing their departures on road trips. Took the uncle 5 hr to load up their camper van for them to actually hit the road. And all the while, the entire 3 days they were here, the uncle kept saying the whole time about how hot it was (we’re in AZ) and how Aunt was going to die from the heat…literally while MIL WAS actually dying. And then we got to listen to the uncle talk incessantly about all the ways he thinks HE is going to die.
And then the aunt & uncle started lecturing my H & SIL about how they needed to have a funeral right away, blah blah blah. MIL didn’t want a funeral, but her friends at her church wanted one, so the church organized a memorial service. Aunt & uncle were not told about it. Oh and aunt & uncle kept hassling H & SIL all Labor Day weekend about doing a graveside service in southern CA (which is where MIL’s cremated remains are buried). A graveside service did not occur (SIL’s decision).
I’ve never seen 2 people make somebody else’s death more about themselves, were it not for witnessing all of that nonsense from the aunt & uncle. Thanks to aunt & uncle’s behavior that my kids witnessed, D24 & D26 now don’t think very highly of aunt & uncle. Aunt & uncle are the sort of people who take a simple task and transform it into something very complicated. Everything they do takes forever and ends up full of drama. Like my sister says, they built their cage around themselves.
I’m so sorry you’ve having to deal with all of this. Do the best you can. Know and expect that negative things will happen which will be beyond your control and you won’t be able to do anything about it. It’s really hard. 
