Every trained nurse and doctor that's not sick will be in deck at actual hospitals, and when it comes to things like intubation - which is going to be required in large numbers, I doubt you could teach people in the time available.
The other problem for you is lack of materials - hospitals don't have oodles of ICU equipment lying around, making the rooms sterile and air-tight would be a touch difficult.
Nice thought, but not at all practical.
The practical measure would be to get armed forces to set up MASH-style hospitals and get ready to lend a hand.
If you are talking about the U.S., we actually do have supplies laying in wait. At least it is in the law and in the budget that they are there.
It is called the
Pandemic and All-Hazards Preparedness and Advancing Innovation Act (PAHPAI). I'll just call it Preparedness Act. It is designed
"in order to make the federal government more effective at preventing and responding to public health security threats such as bioterrorism attacks or disease outbreaks."
Already the Dept of Health and Human Services (which oversees the CDC) has switched leadership specific to coronavirus to the
Assistant Secretary for Preparedness and Response which has full authority (in their Office of Emergency Management) over the
National Disaster Medical System which can mobilize thousands of medical personnel, tap into 1,800 member hospitals, enable doctors to cross state lines, and coordinate partnering with military staff.
Supplies are stockpiled in the
Strategic National Stockpile which can be released by HHS (or Homeland Security if it was bioterrorism, FEMA in disaster, etc..) when local systems are overloaded in an emergency.
None of this, to my knowledge, has been activated as yet. But thousands of additional breathing tubes and ventilators
should be there in dozens of warehouses across the country.
The N95 mask supply does seems to be low as they have already said they could need billions of them and only have 10's of millions on hand. I know California has their own stockpile of 21 million, with some expired, and it isn't enough.
