There don't seem to be stats on this, unfortunately. America is running out of blood though...

https://www.redcrossblood.org/local-...-shortage.html

There are similar articles for AUS, CAN etc. Platelets only last 5 days, so a constant supply is needed.

So it isn't unreasonable to think there are people dying from a lack of blood, or at least that some will in the future. There's over a million Brits living in North America (and even more people who lived in the UK between 1980-1996) who are a potential source of blood.