Plant closing and notice period questions - 2 months and counting

I received a formal notice about a mass layoff at my workplace. I do not know if I should start looking now or wait for severance news. Should I stay for the bonus?

Thanks for writing this out. I went through something close to it 2 months ago, and it settled down once I kept a simple log of every call and form.

Write down key dates and keep copies of the notice. Mine helped when a question came up later.