So 20 % of the US population is 65 million, give or take. Representing the people who get ill enough to need treatment.
0,01 x 65 = 0,65 million
0,02 x 65 = 1,30 million
0,03 x 65 = 1,95 million
and so on. Now, that's the total, but worst case scenario is 40-50% infection rate at this juncture or peak in the curve. Those who dodge the bullet are unlikely to continue to do so, for the simple reason that the time we can all isolate is finite. The clock is ticking for a vaccine.
It still looks pretty dire.