We wouldnt last 18 months. The vulnerable will die if this country collapses also. Which is what will happen by trying to lock down the country for 18 months. Folks will start rioting sooner than later as their retirement accounts go to zero and companies close and layoff.
Yeah, this is also a very real possibility too, and even though the post above I made said that lockdowns are most likely the best case scenario... There's no guarantee things will play out that way. I think this is where innovation is going to have to come into play, because a country without a workforce is lethal for everyone. If there's a way to protect people while going outside, to prevent people from getting sick, that's one option, but it's easier said than done. Some companies are allowing people to work from home, but due to the nature of many businesses (like hospitality, travel, retail, food and entertainment) this isn't possible. People for the most part have to be physically present in order for businesses to make money. If not, they'll just opt for options like Amazon, UberEats and Netflix.
Many companies are doing deliveries for food now, so maybe delivering to customers as well as combining digital shopping might be the next best thing. It can't work for everyone, but maybe going digital and giving people incentives as well as making changes to fit what's going on (like Universal bringing their movies online at $20) could be a good workaround.
I honestly don't know what the solution is, though. I don't know what would be the best move, so I have to assume the leaders in charge who have the resources are aiming towards that scenario. They stand to lose in all of this as well, and it wouldn't make sense for them to not act efficiently.