Too often, people are hung up on the air temperature.
Due to the weight and mass of masonry products the over-riding factor is the temperature of the materials (units, sand, water, etc.). For curing of a wall, the temperature of the materials governs. Any good contractor will have the sand on site over a culvert (and covered) to heat it over night.
While working for a block manufacturer, we typically loaded the trucks the night before (to put the trucks inside the garage during the sub-zero temps). We also palletized the block in a pattern with the faces of the block in the top layers upwards (a "snow cap") to prevent snow from getting into the cores of the block. The lower layers had the cores vertical to drain since all block were on wood pallets ($8.00 or $10.00 deposit).
Fortunately, the contractors were smart enough to prep the site to handle the deliveries instead of just demanding last minute decisions.
Somehow, we managed to sell and deliver 12,000,000 to 16,000,000 block a year and never would meet a competitors price. - Brick were a totally different product because we had them shipped in in whatever size and configuration the brick manufacturer decided.
For winter construction, if you have the basic materials warm enough, the normal curing heat of hydration can proceed to provide strength.
Dick