I'll be blunt, Prognosis is grim here. Once it's at that stage the only thing stopping it is systemic fungicide or a wettable sulphur powder wash, and you cant really do either of those things to something you are going to smoke.
You could try regalia but it's expensive, and I honestly think your infection is beyond curing without harsher pesticides.
12 plants total..only 3 showed any signs.. Ill cut off all infected areas.. Then since they arevin grow bags ill get the hand truck and move un infected up wind plants further up wind..then move infected plants much further down wind and hit em all with regalia... Then maybe Greencure... I gotta fight loosing 10 or so lbs of great bud... The damned bushy 9lb hammer is what got it first..tjat sucks cause the yeild and quality of that is real nice... Hope fully I can save at least half of the crop... ...
Forgot to mention there are 6 diff strains.. 2 strains are 2 weeks out to harvest and didnt appear to be infected... The big bud and ptw are almost ready..maybe 1 to 2 weeks.. The menthol monkey and 9 lb 3 weeks and the Deathstar 3 to 4 weeks
Yeah get those mildew ones as far away as possible, personally I'd tiger torch them, but you could try greencure and regalia. Both are better as preventative though. PM spores go everywhere and only take a week or so to infect everything else once they are released.