Could you explain how you have covered your vegetables, and how much protection you have?
I have two rows of large pots - 5 pots long and side by side. They are all about 5 feet apart.
I put small pots over some of the smaller tomatoes, and a beach towel over that. On the taller ones I just put a beach towel.
Around my pots is a circle of 5 or 6 foot concrete wire.
When I saw your structure, I wondered how many degrees protection I could have gotten if I had used just that fabric, or the fabric with the pots and towels.
If the weather gets to about 32, what do you think it is inside your structure? It all looks so neat and organized.