A few tips:
Your temps are way too low. It is very likely going to stress the plants during the night. In addition you could definitely run into issues with powdery mildew. There will be less of an issue if the air is moving around regularly. If the air remains stagnant with no breeze or regular cycling, powdery mildew can become an issue... and its much worse in colder temps as the humidity is high. If you walk into the tent and can physically feel water droplets on the inside, you'll definitely be in store for some problems ahead.
If you can increase the temperatures you'll be much better off for sure.
I live in the desert so the added humidity is a good thing. Its only 55% humidity. Im buttoning things up. In my posts i keep mentioning temps. I can only run so many heaters. Ill see what it does tomorrow in the morning as the extra heaters were added today. This is just for personal grow not for profit. Not stressing too much on it just a fun little side yard thing.
Yeah, for your conditions what you have going isn't a bad thing at all. Just watch out for that mildew, the better you get that baby sealed up the worse it can get, especially after a good watering. Just a warning cuz I went through that crap recently myself and it was a pain in my ass. I'm in SoCal. Lucky the temperatures allow for greenhouse growth this time of year.
The plants look nice and big man. Probably going to produce lots of buds for you.
It's difficult to grow cannabis outdoors this time of year in north america.