Doesn't really matter. I got laid off recently, and I had 125 thousand bucks in liquid assets, as well as about 200k~ in stocks and shit (probably 100k after this last week...fucking crash).
More than enough to pay for my mortgage and other expenses for quite a while. And if things got really dire, my condo's in a high demand area, so even now I could flip it for over a million and make quite a profit after paying off my mortgage.
YET EVEN WITH ALL THAT, saying no to my severance package would have been pretty hard. Spitting in the face of about 20 thousand bucks (the sum that was agreed on) plus various other benefits, isn't easy.
Fortunately my previous employer was actually pretty great, downsized for good reasons (well, they made mistakes leading to the layoff, but they weren't replacing anyone laid off with cheaper workers or anything), so I can, in good faith, just say the truth and how i really feel, and still not be in conflict of anything in the severance contract.
Not everyone is so lucky.