Well it was pretty much this time last year I got laid off.
My advice: hit the crap hard right now. Many jobs will be filled in January, like a good portion of the year's jobs. Probably already posted. The others throughout the year will be the ones that came open because of people who took those January jobs. Carousel type stuff. Also, the best jobs don't ever get posted. She should use her network right now, and hopefully she has been, so that when a manager is submitting the job req for approval he/she already knows they are going to hire your wife.
Severances absolutely are negotiable. Even if the amount stays the same there is good reason to try to modify the wording of the settlement agreement. For example, she will probably be asked to sign something saying she won't sue the company. There should be some consideration tied to that part of the agreement, or maybe even two separate agreements. So one is a severance and one is a settlement. The settlement portion doesn't affect unemployment eligibility, so get as much in there as you can. Then she can still draw unemployment.