When finishing concrete in cold weather, you still need to wait for all the bleed water to evaporate. Bleed water is basically the concrete particles settling (like mud in a stirred-up pond) and squeezing out all the extra water.
If you finish that water into the surface, you increase the water-cement ratio and get weak surface concrete. Since the concrete is setting more slowly in the cold, bleeding starts later, lasts longer, and you can get more bleed water. You can try getting it off with squeegees or vacuums–or you can wait.
Concrete in cold weather the surface can dry out even faster than in warm weather, if the concrete is warmer than the air.
Concrete sets more slowly when it is cold—very slow below 10°C; below 5°C the hydration reaction basically stops, and the concrete doesn’t gain strength.
These are concrete temperatures not air temperatures.

ARMOURTECH PRO Float slows down moisture?loss, allowing cement hydration to proceed properly, which extends workability time in hot, windy and low humidity conditions when needed. Eliminates the need for water to be added to concrete. It does not mean the concrete will take longer to set and cure it just gives you a little more time to work with it and finish it properly.

ARMOURTECH PRO Float and finishing times in cold temperatures.

The question will ARMOURTECH PRO Float increase the finishing time of the concrete in cold weather and hence put more pressure on the placement of the concrete?

The reality is that the ARMOURTECH PRO Float in cold conditions will only affect the finishing time by speeding it up not slowing it down.

ARMOURTECH PRO Float promotes ease of troweling which actually speeds up the finishing.
ARMOURTECH PRO Float produces a more workable surface reducing the work/time needed to finish surface properly. This is saving time and money and it eliminates the need to add water.
ARMOURTECH PRO Float actually provides a denser surface allowing quicker access to the surface.

In adverse conditions including wind, high heat, and low humidity, ARMOURTECH PRO Float really provides the advantage of increasing the working time by 25 –30 minutes, which allows the slab to be closed off properly. ARMOURTECH PRO Float can make the difference between a satisfied customer and a costly callback.

Finishing and Curing are 2 separate functions. The finishing time does not affect the curing time and the same is true that the curing is not affected by the finishing time.
ARMOURTECH PRO Float allows for easier, more complete high-quality finishing while assisting the concrete to Hydrate and cure effectively.
Curing is giving the concrete what it needs to gain strength properly. Concrete strength depends on the reaction between Portland cement and water—Hydration.

Since the concrete is setting more slowly in the cold, bleeding starts later lasts longer, and you can get more bleed water. If you finish that water into the surface, you increase the water-cement ratio and get weak surface concrete. ARMOURTECH PRO Float avoids this by eliminating the addition of added water to the slab surface.

Promoting the proper Hydration of the concrete with ARMOURTECH PRO Float has a positive effect on the finishing time even in cold weather.