We were supposed to go down to 38° here with a wind chill of 30°. I was surprised to learn wind chill and "feels like" temps matter not to plants. What affects them is actual temperature.
That being said, I got to practice covering some stuff, just because the way weather forecasts can be off and that was some cold air up north.
I used 6' tall bamboo stakes and wrapped them in frost cloth. Should we have been forecast to freeze, my plan would be to place "candle heaters" in the covered shelter.
Maybe with the bigger trees, I would try a similar setup, but without being able to cover the tops of the tall ones, hope the rising warm air from the candle heaters would help some? Hopefully I'll never need to experiment with that.
Per my car's thermostat, the lowest I got here was 42°.