Pennzoil and most other majors (Valvoline is the exception) don't publish TBN numbers, so you your options are waiting until PQIA tests more 0w-20s or send a sample of fresh oil into Blackstone for a "virgin oil analysis".
PQIA has tested a few similar 0w/20s and found the following TBNs:
Mobil1 AFE: 8.8
QSUD: 8.3
Castrol with FST: 11.6
PPPP doesn't claim to be an extended drain interval oil, so an educated guess would be a TBN in the 8-9 range, as k24a4 notes.
I put PPP+ 0w20 in my 2013 Accord about a week ago. As already said above, it is a great price now.
I plan to do a UOA with TBN when I change my oil. It would be interesting to see how much it changes with my type of driving. I change my oil shortly after the OLM his 15% remaining. Most likely that will take about 9 or10 months so I have time to wait for someone to test it.