Nortel did the leg work. They reached the decision that they would be able to maximize their return by selling the entire patent portfolio. I don't expect InterDigital's management (nor their advisors) to waste any time following the exact timeline Nortel did taking the same considerations every step of the way. Again, Nortel created a successful model/market on how to sell an entire patent portfolio.
The acquirers showed that they highly value the defensive capabilities and/or nuclear capabilities of those Nortel patents and will pay a premium for such. One potential acquirer of the Nortel patents, Google, lost out and now has to find an alternative which is our InterDigital. During their Due Diligence they, and the others, likely came across IDCC and used it in their modeling because IDCC provided them the ability to forecast and NPV to see the potential returns of a patent portfolio company licensing it's technology.
IDCC Management may not have reached a final decision as to how they will sell the company but are likely leaning towards one way, a complete sale because of the path that Nortel took. This path appears to maximize the end result. What ever path resulted in $4.5 billion on a sale that initially was expected to only produce $1 billion is likely the correct path.
Just sayin', this will not take years to complete, this will take months.