Oh, goodie! I hope it works out for you. I had lettuces until December last year.
I have to fill the last one with the seed mix yet, but I’ve got time. I also see some spinach I planted outside failed to germinate, so that needs a re-plant.
Even on 50 degree days now, it’s 80 and above in the greenhouse. Terrific for germination if I remember to keep everything moist. ;)
Slightly different situation for me.
My “greenhouse” is a 4 by 16 ft structure on my south wall.
With low mass.
It yields heat an hour after the sun comes up- no matter the outside temp. I send that into the house.
BTW, I used “4 year” film - that’s lasted 10 years and is just now starting to show degradation!
https://www.growerssolution.com/PROD/4-year-6-mil-clear-greenhouse-film/G4Y6MGF