Severance offer, what should I ask for? - 14 months and counting

My manager said the package is final, but the letter gives me time to review. It has been a long 7 weeks. It includes health coverage for a couple of months. Did anyone negotiate and succeed?

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.