You can look at the numbers from China where they were going door to door. If you do then you get closer to the 1.5% the problem if you read the reports on China is that when someone was asymptomatic they didn't include them in the results of confirmed cases even though they tested positive. Probably because it allowed the powers at be in China the ability to down play the number infected.Not if the real mortality rate is much less. If the reality is 0.1% like the flu then 70% infected would be around 228,000 deaths in the US.
Until someone goes out and samples a large swath of the population, we have absolutely no idea how many were/are infected with asymptomatic or very mild cases.