Is there any chance that European Portuguese may be added in the near future?
You could do these:
I doubt Duolingo is going to add an European Portuguese course. Memrise is quite fun, might have to read up on grammar somewhere else though. If I recall correctly, I think I read on Twitter that Memrise is going to get grammar notes though, for the official courses.
I like to start with the wiki article on grammar: https://en.wikipedia.org/wiki/Portuguese_grammar