Hi,
Just wanted to chip in, we're in some kind of a similar situation.. Passport will expire on August 2016. We have done our Medicals recently, we're hoping to have the 3rd line soon and the inevitable PPR by God's Grace thereafter.
Actually, we didn't had the time to make appointment with the Phil Embassy here in SG for the said renewal. And we know for the fact that it will take some 2months for the new passport to be released. So, we have decided to wait for the PPR and submit this current PP for stamping. Afterwhich, once PP is back with Visa.. We'll schedule for renewal.
I have done some researched online and here within the forums. Others have done this as well. So, during landing.. U just need to produce the 2 passports, the invalid or expired with the Visa and the renewed PP. Since Visa has it's own expiry and not dependent on the passport.
Not suggesting you do the same. Just an option to consider as well..
God bless