I was WFR'd approximately 2 weeks ago. Severance is 60 days pay (on target incentive) and at the end of 60 days you have to sign a form that basically makes it impossible for HPE to ever hire you back again. For signing the form and returning it within 5 days, you receive approximately one months pay.
Benefits? Gone immediately. Cobra is your only option if you want to pay a ton for benefits and not risk it.
Unused vacation pay? You just forfeited it according to the WFR guidelines.
You have 60 days to be rehired by HPE. Except that for the last week or so, there are no open job requisitions available. Meaning you must wait until after November 1st when FY17 starts and hope that some jobs start opening up. Competition for those jobs will likely be fierce as people seek to grab the fastest, easiest way to re-employment.
Then they can sit and worry about the next round of WFR's, which are inevitable. Best option is to probably get rehired and then immediately start looking for another job. HPE's job cuts make no sense, unless the sense is only that they are reducing cost.