Is the thinking here that increased scale would allow production to get cheaper? How would this account for the fact that production was scaled here, but was not cost-competitive when it was operating at scale? What's different now?
Of course that assumes your own costs (like raw materials) do not increase at least on the same scale and that you can rely on the situation being long-term thing (i.e. will last years rather than weeks) as costs include your CapEx on things like new machines.
So here we are assuming that we could get a 50% reduction in cost by scaling to 1m units of a thing. The problem with this logic is that many product categories currently made overseas were produced domestically at scale until relatively recently.
This assumption also appears to imply that the goods in question either have a very low labor input or are produced using automation that is not available to Chinese manufacturers.
Reframing my initial question, what advantages would a US manufacturer have today that they didn't have in e.g. 1990 that would allow them to manufacture for only 66% more than the same manufacturing in China?