Neem can be used up to about the last week or so before harvest.
It has a sent but only when it's applied(smells like piss kind of)citrus piss..The buds at harvest have no evidence of anything other then killer bud.It's organic and natural and MJ is very tallerable of it...but still do the bottom branch test.
So you can get the measurment right for your strain.

Works just as well or better then that soap stuff.Spray the whole plant top and bottom of leaves(every inch)But be careful not to let to much soak into the growing medium...can fry roots.I never had this problem.I think people who do are applieing to strong of a solution.
Any more ?'s just ask.
65 is the lowest I'd go with the temp...it's not ideal for the buds but the buds will be crap if you don't get rid of the mites.If anything the low temp might barley slow growth(but I doubt it.)
and the temp thing makes a huge difference.they love hot dry weather and thrive in it,so make your room the oppossite of that cold and spray the buggers every other day with neem.For like 3 weeks at least.