Socialized systems do not fail right away. They rot out from the inside over a long period of time. It took a good long time for NHS to achieve its current state of decrepitude. A US collapse will take a good long time too, perhaps 60 years.
But the collapse started when Medicaid and Medicare shifted incentives in medicine in the mid 1960s. We're at year 50 in the countdown but our half private/half socialized system will not fail in the same manner. The NHS got as bad as it is today with 60 years history of controlling far more of medicine in the UK than Medicare and Medicaid control in the US.
Certain parts of the system may break very quickly. Others may take decades to be ground down to the poor care levels outlined in those three damning reports. The truly worrying bit is we don't know which bits are on their last legs, waiting for Obamacare to plow them under and which bits will survive, for now. We won't know until systems start to fail.