If there's not a formula in mind, it might be easiest to give immigration authorities the power to quarantine new migrants if it is determined by the CDC/Health Department that not enough testing kits are available.
I think this idea would be preferable for executing this policy if we must quarantine new arrivals.
As for the quarantining itself, I feel like it's too late for it to help the situation here in Atlasia since the virus has already spread throughout the country and would not be worth the damage to our economy to not allow travel into the country.
What works for New Zealand and Australia is not going to work as ideally as expected in a country like ours which isn't on an island that can easily be quarantined.
