There was a thaw, and the marshes west of the Studenka ford were impassable for vehicles before the night of 23-24 November. That evening the temperature dropped and by the 25th those marshes were again frozen and it only got colder during the operation. Bridging operations didn't begin at Studenka until the night of 25-26 November.
The first troops crossed the ford as the bridges were not yet finished at about 0800 on 26 November. The actual construction of the bridges in the river began after the advance guard reached the west bank of the river. The infantry bridge was finished at 1300 26 November and the vehicular bridge at 1600.
By this time the marshes were frozen enough to allow troops to maneuver off the roads.
I have Mikaberidze's volume and Arnoldi makes the comment about the terrain close to the river, not further on where the French would have to go to move off the field and continue westward or to form their units to defend the bridgehead. And Arnoldi does not, as far as I can see, give his position in relation to the Studenka ford or the bridges, only that he was out of range of the French massed artillery on the ridge on the east bank. The French artillery was emplaced there to cover the crossing, and if Arnoldi was out of range he was over 1,000 yards from the French artillery and the river was only 100 years wide.