I loved it!
Yes, I’ve watched the entire TV show, but only once through, and not since it all ended. That said, the various subplots came back to me once I watched the movie. It can be enjoyed without watching the series, but is much more rewarding if you’ve already since the tv series.
Plus, the film does allude to many plotlines from the TV show, so rather than spoil them by watching tthe film first, I would recommend to watch the TV show, then the movie.
I liked how the film ended, it reminded me a lot of a film called The Leopard.