Yes, I think our nation's infrastructure could recover from a significant cyber warfare attack, because all of that information is still somewhere. Network hardware would likely not be affected. Websites could be recreated. We could go back to doing things on paper until the systems could be rebuilt. We would recover in time.
As we switch to a more automated infrastructure, we have not taken the time to harden and isolate the systems. The systems themselves are extremely vulnerable to attack. The interconnectedness is what slows the recovery portion though. Almost all of the grids are connected. These connections can be exploited to spread whatever virus is introduced. Also, if you shut power off to an area, getting other infrastructure back online will be impossible.
I believe our nations infrastructure would be unaffected by a significant cyberwarfare attack. A cyberwarefare attack is usually carried out by hacking systems to gain information or disrupt a computer system. Infrastructure includes roadways, buildings, power grids, and the life. Infrastructure is not affected by cyberwarfare attacks. Cyberwarfare attacks essentially keep infrastructure in tact with the exception of networks and computer systems, which aren't really considered infrastructure.
I think we are so weak right now that any attack would crush us, we have little give left. The amount of information either in banking or secret that is digitized is outrageous. It would be a win if anyone could crush the stock market for a solid week or so,even attacking the debt of the major banks would crush the secret.