I need Heat!!

So over the past few days about a foot of snow has set in and temps have not only dropped outside but are dropping in my grow room. I have never had a problem with not having enough heat, my temp in flower room has dropped to 67, which normally during lites out, it never drops below 70, actually 72 has been my lowest temp in 3 grows. I already have small heater and until now it has worked fine.
My question is should I add more heat, will the low temps cause stress and make them hermy or is 67 ok?
I have one more heater I can add, but I really need it in veg room because temps have dropped considerably in there as well. I only have T8s in there for clones and Mama and temps are very low around 60, but if I have to sacrifice all that to keep my flower room from stressing I will.
I know that buying more heat is more than likely my best option, but as we all know times are hard and if no need to spend the money then why spend it.
Thanks for any help...

60F is about as low as you want to go, anything lower and the plant will begin to negatively behave. So 67F in flower is just fine, keep your heater in the veg room.

you could always make a heat sink out of bottles painted black filled with hot water itll also collect heat during lights on make sure the bottles are sealed though otherwise it might effect your humidity

Well, this is the problem I'm having. The temps are below zero here. I have 2 plants that could be harvested, but my "main" room is getting down to 32! I'm afraid of my girls freezing while drying! I don't know what to do. I have a heater in my veg room and the temp is stay ok'ish. The temp in my flowering room has dropped to 42! I can't add more heaters or my breakers/heaters/lights blow. What will happen to my plants? Should I harvest or wait for it to warm up a bit?

Better to harvest now... that's well below the reccomended low for growing indoors.

Turn your fans off at night? Or right before they go off.
go get a dehumidifier to heat your room at night.

just hook up another heater, or what kinda lights are you using? maybe some HIDs can heat things up.

mine is always at 68-69 during winter.. no problems

Yeah, that's fine. In the winter, mine hover at about 77* with light's on, and around 65* when the lights are off. They never complained once, to my knowledge. Or, maybe they just kept their mouths shut, so they would get their dinner?lol

67 is a bit too low.

If you do nothing and your guys still go strong (they are weeds after all) the bud will prob be more purple than anything... not strain purple temp purple.

I ran into the same problem with low temps back at the beginning of December. I solved my problem with a 48x20 seedling heat mat from Hydrofarm. Works great!

Thanks for all the great info and remedies for solving my temp issues. I actually think I battled through the cold spells like a pro some leaves started to curl on the plants closest to the door but, soon after we had a warm up and things were looking fine.
Now new problem, I am 24 days into flower and things like I said earlier are looking great and had to leave town for funeral, so I have a guy come check on things for me, and when I get back after 3 days, 6 outta 8 seemed to have kicked the bucket. Its almost like the guy poured straight nutes or something. They are in such bad shape it is crazy. leaves just burnt. crispy, brown, I dont understand...
he says he only watered once, but water doesnt do that.
There is some green left, very tiny leaves close to flowers that are kinda krispy on edges but so are flowers.
If it was nutes that did this, can they be saved by some hard core flushing or am i better off to just count my losses save time and effort and move on.
really disgusted...oh yeah clones dead too, surely cold spell didnt kill them two and ahlf weeks after the fact