While "managing to build a night camp" might give the impression of an orderly retreat after the first day, the extensive source on the battle, the Roman History of Dio Cassius (other sources not giving a lot of details), makes it clear the Roman army was in disarray.

For the Romans [...] unable to form readily anywhere in a body, and being fewer at every point than their assailants, they suffered greatly and could offer no resistance at all.

Accordingly they encamped on the spot, after securing a suitable place, so far as that was possible on a wooded mountain; and afterwards they either burned or abandoned most of their waggons and everything else that was not absolutely necessary to them. [Roman History; Dio Cassius; L, 20-21]

There we have a Roman army, that have suffered significant losses both in numbers and material, managing to hold out long enough German harassments and attacks to hastily make a camp on a difficult ground and burning out the baggage they could spare. Eventually, they simply don't seem to have been in any shape to mount an efficient counter-attack in the wooden and mountainous area where they could be ambushed anew, as the accounts for the second and third days could point out.

The next day they advanced in a little better order, and even reached open country, though they did not get off without loss. Upon setting out from there they plunged into the woods again, where they defended themselves against their assailants, but suffered their heaviest losses while doing so. For since they had to form their lines in a narrow space, in order that the cavalry and infantry together might run down the enemy, they collided frequently with one another and with the trees. [idem.]

All the that while, even before the tempest of the fourth day nailed down the Romans, more Germans warriors flew in the forest increasing the pressure on them. Arminius' plan simply trapped the Romans as well it could possibly have : inflicting devastating tactical and logistical losses the first day and eventually forcing the Romans to move around while pursuing them with more men.