In this job market, that may not be enough time to feel comfortable and safe taking the offer (if you're a super-employable hotshot with offers awaiting in your LinkedIn, you're probably not the likely target for the offer)
but if I was that employable, and offered that severance, I'd not give it one second's thought
and that's the problem, these severance packages are more often taken by the best people in the company
Could still be much better than a sudden layoff though.