Very implausible scenario...I cannot think of any valid reason (sane or insane) that would force me to contemplate crossing a river such as you have suggested.

Most river crossings are risky enough even at low water.

Attempting a river crossing(regardless of method used) in winter where the water and ambient temps may be in the freezing range is suicide. One fall into the river and without anyone to quickly rescue you, the ice cold water will immobilize your muscles within seconds..then you are a dead man/woman.