If I lost my cofounder (who isn't a migrant) I would be devastated and probably wouldn't produce much of anything for a year or two.
If they were from another country and I didn't even have any of my cofounder's family around, just a big gaping hole where they used to be... I'd probably quit and go find a job somewhere else so I could stop thinking about it.
Getting a patent application in would be the very last thing on my mind.