Why do people want to get tested? There's no demonstrated effective antivirals. There's nothing they can do for you in the "I might have it" stage. All you can do trying to get tested is get exposed. Let the hospitals worry about that. Only go there or to clinics if you have to.
I think most people who want to get tested just want to know for sure whether they have it or not--which may or may not make any difference in how they conduct themselves.
Also, I've seen reports that some employers have claimed they will pay corona-stricken employees who have to go on quarantine--which sounds magnanimous until you realize those employees will have to prove they actually have coronavirus in order to get paid. If they can't get tested, they're SOL.
And, in the coming days, there may be relief programs available through various government agencies, as well as private charities, for people who had to stop working due to coronavirus, and they're going to want proof of infection, too.
So not only is failure to provide widespread testing completely distorting the official numbers, but it's potentially going to keep a lot of people who might desperately need financial assistance from qualifying for it.
I already have a stockpile of MREs and nonperishables because I live in earthquake country. I think most people in California should have a couple of weeks of supplies, since Northridge is in recent memory and we have low-magnitude tremors all the time.
Anybody who lives on the West Coast, all the way up to Alaska, should have at least a couple weeks' worth of supplies in case of a major earthquake. I'm so routinely amazed at how few people do that I should just stop being amazed at all and accept that the great bulk of humanity is fundamentally short-sighted and stupid, no matter how well-educated and successful some of them might seem.
Stay in comfy apartment in major city and epidemic center where you know many neighbors (highly likely to be quarantined if it comes to that) or flee to grimy, empty house (everything works but needs reno and serious cleaning, no furniture) in a pretty small, safe town with a yard where you know no one?
Stay. Sheltering in place in a clean, comfortable apartment, in a city where you know people, where they know you, and where you know how to access any services you might need, is preferable in this case. There is an understandable impulse to run that I see expressed a lot right now, but staying in a familiar place is going to be a lot less stressful.
All right, real question.
If someone's in a "hot" zone, one of the "in two weeks we're gonna be Italy" spots and they're following the recommendations in this thread and elsewhere to stay home, how long would they need to do so to appreciably improve their situation? Would staying home for a week right now make a significant difference? Two weeks? A month? Do we have any idea how much time would be needed or when the optimal time would be?
As someone who lives in a zone such as you describe, I can honestly say I have no idea. We're in uncharted territory. I've got possible symptoms, have been home for a full week now, and expect to remain here until at least the end of the month, even after the symptoms are gone. It could end up being longer; I honestly don't know. The best I think anyone can do is avoid going out as much as possible, keep an eye on the news and social media, and keep making decisions on a day-by-day basis, given whatever information is currently available.
There really are no solid answers to questions like this right now, which is already making some people crazy. Personally, I think the healthiest response is going to be accepting that you don't know when things will return to some sort of "normal" again, while reassuring yourself that eventually they will. Countless people across the span of human history have survived a lot worse shit than this, without knowing when it was going to end, and you will too.
Take care of what's in front of you in the present; try to anticipate what's coming up next in the immediate future so you can deal with that, and try to do something every day that gives you some joy and helps you feel more normal. If you're stuck at home, keep to your regular schedule--don't stay up shitposting half the night only to end up sleeping through half the day (unless that's what you normally do). Get outside whenever you can.
I'm aftaid that's the best I can tell you. But we will get through this.