We are in mid autumn and they are calling for snow Friday. We grow in an unfinished basement originally built in 1947 so whatever temp it is outside it'll be close to that in the basement without some intervention. I had to disconnect the heat duct that goes to our bathroom in the basement so we get a little heat but without insulation the temp drops rapidly when the heat goes off. It never gets below freezing down there but i've seen ice on the walls in the storage room down there when it's really cold. Hopefully covering all the walls with plastic sheeting plus the 2 HID lights will keep it in the 70s with the tents closed. I know we'll figure it out. Another problem is the cost for heating our house costs 3x more than last winter. Its going to be a very challenging winter for us on all fronts.
Sounds like you’ll have to improvise at some stage . Electricity for us down under especially the state I live in cost wise is ridiculous. My last 3 months usage bill was like $1200 US dollars . Admittedly that was through winter with my wife’s hair salon tapped into it as well but still expensive .
My winter temp in the room dropped to 40-45 F during the night which caused what looked to me like lock out and they pretty well went stagnant in growth and eventually yellowed and struggled . Was only when I threw an oil radiator in the room and raised temps they recovered and recommenced growth .
Then in Summer I’ll have to look at increasing airflow . I have an 8inch Infinty only set on about number 3 otherwise it’s too noisy at night when it’s calm so I may have to look at ducting it up into my roof cavity instead of out the window to reduce noise .