We saw this at the Palm Springs Film Festival in Jan. 2019. Our question after seeing a movie is always "Could this can been improved?" In this case, the answer is a firm "No." It's pretty much perfect within the bounds of what it set out to do. It tells a realistic story in a straightforward way (no time shifting! Hurray!). It held our attention throughout--no looking at watches. It's pretty much Brian Cox's movie since he is in every scene, and he does a great job. He had to learn Gaelic to play the part, and as far as I can see did a fantastic job.
Is it a comedy or a drama? Both. Certainly the comedic angle is almost always there, but there are touches (esp. the scenes with Rosanna Arquette) where it gets fairly serious and has a serious message. But it never hits you over the head with sentimentality or its "message." The director seems to have found a perfect middle ground. This seems to be getting rarer, so congratulations are in order.
Finally, it reminded me of a 2016 Finnish movie, "The Grump," which also featured a older man who lived in the countryside who visits his son in the big city (Helsinki, in this case). He is technologically inept, leading to several hilarious scenes, and he interferes in his daughter-in-law's business. It was more of a pure comedy than "Etruscan Smile." Curiously, neither Brian Cox nor the director were aware of the Finnish movie.