Will we lose our FPP if we use tix before upgrading?

We have 5 day ph as part of pkg since we had to buy same for everyone on the reservation but plan to upgrade 4 of us to AP while there. The 1st day we arrive in the evening and plan on MK emh that night. If we book 5 days of FPP at 60 days out then use our tickets to enter the park without having or using FPP that day, will we lose any of the remaining 5 days of FPP since we would have only 4 days of park entry left on our tickets?

No. You will not lose them. We had 3 5'day PH's in Feb, upgraded 2 of them to APs during the trip and all our FPP's still worked for everyone the whole trip.

Thanks, good to know!