Can we instead of make some changes on local level that effectively work with the climate change or minimise the impact? Might mean need to abandon some locations, but there has always been population movements.
We are not turning back the systems that will heat the world.
If we approach it as a local challenge, there is a chance we can invent new ways to deal with it.
Maybe instead of this being the end, it could be a beginning of new science and development that counters the negative impacts of change.
Maybe, just maybe, we can get some good out of it.
How many would be able to live like this, how many would die until we would get to this point, and do we really want this?
The problem is the overconsumption and overpollution. That's the only problem.
Nothing good would come from your proposed solution, imho.
We can always get our towns ready to receive the millions of climate refugees we'll be creating.
Towns and cities are actually far more resource efficient than rural and suburban sprawl.
The only inefficient thing in them is highrises. But five-story buildings are incredibly infrastructure-efficient. Walking through a midrise neighborhood puts you past more people per minute, than driving 120 mph through a suburb.
When everything works as intended. In a collapse everything changes.
Imagine energy grid not working, no tap water, non-existent food supply, money is worthless ... such kind of future.
Unless you're a subsistence peasant, which 99.9% of rural and semi-rural (suruban) people aren't, you're going to have the same exact problems from a lack of all those things.