Yes: if a government is unwilling or unable to provide for the basic necessities of life for all of its citizens in times of crisis, such as food and healthcare, such measures may be impracticable.
As to the death toll, we simply don't know. I said 700 million as an upper bound: if all humans are infected around the same time, and if 12% of those infected suffer very serious effects (as some statistics from China show), and if those cannot be hospitalised (no country has nearly that large a capacity), then you could be looking at 700 million in theory. I think it will probably be less even…