Peter Tsouras's compilation book "cold war hot" (can be had for a few bucks on amazon) details two "victory" in Vietnam scenario's
one involves the US running highly effective infrastructure building projects in SV along with sending loads of civi's and peace corp types. They pour money into the country to make them economically viable, and the military presence is only advisery or for defensive purposes (almost all military aid is sent build up the SV army) it ends up taking more than a decade
the other one has the us launch a massive invasion of NV in 1970 including sending a full mechanized corps across the dmz and landing marines at haipong... neutral ports funneling gear and supplies to the nva are blockaded and the US catches the NVA flatfooted and slashes their jugular in a matter of days
Anyway, and totally off topic the best scenario is the "cheap Greek wine" and stolichnaya! wins WWIII!!!1
That second one doesn't seem very plausible, to say the least. The DRV was a totally mobilized country and all effort was directed to the war. Therefore, the PAVN was well-stocked and well-supplied. More importantly, they were well trained and had more firepower and assets in the North than they ever did in the South, in addition to probably more manpower.
So yeah, option 1 is a lot better.
Yes but almost the entire NVA was south, so it could do nothing about it. Its not an impossible scenario tactically or strategically, but politically.
No way would the US gov could do something like that without fearing an escalation ...
Yes option 1 ( OTL they try to do it, like the Brits in Malaysia ) has more chances of working ... if they would have done it right instead using their asses to do the thinking.