Depends. If all of europe goes italy's way(overwhelmed healthcare system), probably close to a million
Otherwise might be kept in the high tens of thousands/low hundreds thousands
700m people in Europe. If the new sensible restrictions many countries are doing keep the rate of infections to 10% (the current projections vary from 20-60% to 50-70%) with a mortality rate of only 1% (that is doing as good as Korea, Italy is getting 7% right now), put the number to 700k people. Bear in mind, this is probably better than the best-case scenario.
On the other hand, UK's sensible strategy of let's get everyone infected at the same time: 66.5million, 70% get infected, fatality rate of 4% (the system gets overwhelmed so fatalities go up), puts the number of dead people to 2 million.
Probably it is gonna be somewhere in between, so maybe 10m in Europe. Hopefully, we do much better, China and South Korea are showing that it is possible to contain the virus (at least temporarily), maybe the summer makes things better, maybe we soon find anti-virals that can fight it. In that case, it would probably be just in tens of thousands.
I think it is more likely to be in tens of millions (worldwide).