You have created a false situation where the only alternatives are bad ones. If you truly cannot go around the swollen river, the only safe alternative is to wait it out. Find a safe spot on higher ground where you can build a camp and wait.
Patience is your best asset in such a situation, although in the real world you will have other options.
Crossing a swollen river like you described by yourself is extremely dangerous, especially in the winter.
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Warning - I am not an expert on anything having to do with this forum, but that won't stop me from saying what I think.

Bob