NY Times now reports estimates of up to 1500 undetected cases in Washington state alone (https://www.nytimes.com/2020/03/01/world/coronavirus-news.ht...). Though that is a a rough order-of-magnitude guesstimate based on virus analysis in Institute for Disease Modeling in Bellevue, Wash; however, it's reasonable to say that while there are some 70 confirmed individuals, we have evidence to say that there are much more cases in USA than that, we just haven't found them, and haven't isolated them, so they'll continue spreading the disease.

My suggestion would be to prepare for the possibility of a major disruption in 2 to 6 weeks, not 2 to 6 months, given what we've seen of how fast the number of cases have grown in other countries.