It may not be as a great of a deal as you think. I'm a former Oracle employee who was RIF'd. My severance pay was taxed upfront before disbursement. At the federal level it's taxed differently than regular payroll and I received about 1/2 of the gross payout. Don't get me wrong. I was happy to get it. But I was expecting the gross amount and figured I'd owe the tax at the end of the year. So I was shocked when I was not only taxed, but taxed at a higher rate than my normal payroll.
The federal tax it at the "supplemental" rate, which on the surface might seem like a lower or somewhat equal rate than your normal tax rate. But regular income tax is a progressive tax, whereas the supplemental rate is a flat tax.
You'll also be without health insurance. I was offered CORBA which was administered through a third-party company. It was about $600/mo for myself (more for spouses/dependents). The company was a nightmare to deal with and I dropped the coverage after a few months.
IMO, you'd be better off to start looking somewhere else. I would not tell anyone at Oracle you're looking. As someone noted, they just may fire you.