Microsoft’s director of product security has said that he wants to eliminate patching of Windows altogether, but in the short-term wants to extend the patch cycle to six months

Microsoft would like extend its Windows patch cycle from once a month to once every six months, but only after the company is confident its customers will remain safe between the updates.

I don’t think it’s going to happen. Ten years ago it might have worked, but the pace of finding flaws and exploiting them has grown to be so rapid that it’s impractical. Unless, of course, Microsoft just gives up on patching Windows all together. That would push so many users towards Linux that I’m pretty sure it’s not going to happen.