Word-final -ę is usually pronounced like -e, except for cases where it can be ambiguous.
If the subject was implied, you should pronounce -ę fully to distinguish between piję and pije. But in this example, the subject is explicit, so it's not needed.
Of course, in colloquial speech this may vary.
Ę at the end of a word loses its nasality, but you can nasalize it really subtly, especially when otherwise it would be ambiguous. For example:
- ja piję (I drink) - no nasality, subject is specified explicitly
- piję (I drink, I is implied) - nasalize gently, otherwise it would mean he/she/it drinks (pije)
I see that we the helpers are so eager to give info, that it gets confusing ><.
Yes, "ę" is a nasalized sound, but if it's hard to nasalize, then saying "en" or "em" in a middle of the word, or an "e" in an end of the word is perfectly OK.
In fact, it's a correct way of pronouncing words where "ę" is hard to say, like in "zęby" (means "teeth", it's pronounced as if it was written [zemby].)
It's hard to notice for the most Poles, because we just try for a nasalized, and then roll with whatever comes out.
Maybe just go with what the speaker says?
Cognates include Lithuanian puotà (“drinking spree, wassail”), Old Prussian pōuton (“to drink”), poieiti (“drink (imperative)”), Sanskritपाति (pāti, “he drinks”), पाययति (pāyayati, “to give to drink”), Ancient Greek πόσις (pósis, “the act of drinking”), πίνω (pínō, “I drink”), Latin pōtus (“drunk, having been drunk”), and (from reduplicated present stem) Sanskrit पिबति (pibati, “he drinks”), पीत (pīta, “drunk”), Latin bibō (“I drink”)(< *pibō), Albanian pi (“I drink”), Old Irish ibim (“I drink”).