Not sure what you mean by toxic soil conditions…
were you flushing to clear out excess salts or something?
If so, you could run like 3x pot volume plain water or light feed through, then finish the flush with a light feeding and resume as usual. I tried making my own super soil once, and cooked a few plants. To fix it I had to flush out as much as I could… they recovered.
Cold is not good.
I think most would suggest keeping the plants at 65 to 80 degrees or 70 to 85 degrees?
I’m starting a new grow soon and trying to decide whether to bring a grow tent up from the basement grow room to a bedroom upstairs where it will be easier to keep warm… narrower range of low/high temp variations. So many things to dial in the environment…
Lights on 11/13, and plenty of it… and I bet they’ll at least finish out the existing flowers
Then whack 'em in a couple of weeks if that’s the last of the flowering plants.
If you have other plants flowering, let them go until they finish… whatever it takes.