I do not mean to be patronizing, but this is literally life or death and the math is very simple.
Today there are k infected people. Tomorrow there will be kn people.
If n is unsustainable, any positive value for k is equivalent. Arbitrarily large changes to k today make an arbitrarily small contribution to the final doubling.
“Infected people streaming in” means k becomes k+c. How much does reducing c flatten the curve? How much does it increase the time span of the critical last few doublings?
It doesn’t. That’s only dependent on n.
Ok, we can’t “flatten” the curve, but we can move the peak, right? How much does reducing c move the peak?
Well, every day we prevent k additional people from entering buys us one day. Remember, tomorrow that’s kn. Act fast.
If we could, this week alone, prevent a quantity of infected Europeans equal to the infected population already within the US from entering, that buys us one single doubling period before the collapse of healthcare. Maybe a week if we got lucky.
I will guesstimate that that is not a realistic target in fact. The actual benefit scales proportionally.
And next week it’s the same work for half the benefit.
What are you talking about.