Great use of xmas lights, Sirtanon!
Very festive as well as comforting for the plants.
And use of mass is spot on.
I was astounded to see the tomato plant remains I hadn't clipped/dumped have stayed alive and flowering in the greenhouse through mid December, with daytime temps no more than 40's and plenty of nights that dipped below freezing - just not enough to freeze the soil.
There's one key treatment that has emerged here mainly through Vladimir's research and work, which is do not water the plants before a freeze. They do much better and endure much lower temperatures if the soil is fairly dry. I have confirmed that myself by watering some outdoor plants and not others. And the plants in my greenhouse this year haven't been watered since October, this is why they kept on. I also wonder how much the maturity of the plant plays a role - late season hardiness always seems more robust than early.
In the end, I couldn't resist dragging the last two 'plants' indoors just before our first heavy dump of snow. The longer stem sadly didn't respond well to being warmed fed and watered, I guess it was long since compromised but didn't have the moisture to actually rot. I trimmed off the healthy flowering sprouts and put them in water to see if they root. They were the best tasting of the lot, so the prospect of even a few lonely fresh maters during the winter was too much for me...
I guess your season is just starting, so best of luck with those!