other studies would indicate its more like 55-85 times the number of cases reported
Not in my country. In the Czech Republic, staff and clients at care homes (about 13,000 people) were tested for antibodies. 38 of them had antibodies, which is approximately 0.3%. The population of my country is about 10 million people and we have about 7,000 reported cases, which is 0.07% of the population. It would mean that the real number of exposed people is 4-5 times the number of reported cases.
Another testing of 27,000 people is underway, and we should know the results in early May.