I don't want to bag on Matthew Morrison, partially because his performance is genuinely not worth dissecting. He isn't the Grinch. I am all for the power of transformation with any actor, but this wasn't a test of transformation. Because our modern culture has mainly seen the character of the Grinch through the live-action Jim Carrey version, WHICH IS ICONIC, most audiences associate the character of the Grinch as a "more comedic and smarmy Scrooge". The Grinch story is a beautiful story but the only way it works is if it's done with the campy-ness and stylization that the Seuss world exists in. Matthew Morrison was in a completely different show than everybody else during that filmed production.
As far as the concept of the special, I thought it was cute. It was long, it dragged, and I could've used less musical numbers with the Grinch and Max. I thought this would have been better executed if they actually tried to adapt the musical to the screen as opposed to the other way around. Filmed productions are obviously hard. Musicals are ridiculously hard. I loved the idea of the pop-up book! I wish they would've just tried to not film it like a sitcom or "live musical" and actually make it a made-for-television movie musical! If I was a kid, I'm not sure if I would have the patience to sit through that thing.
The live-action movie is successful because the audience watching the movie realizes that this children's book is coming to life and because it's a full length story, naturally there is room for breaking the 4th wall. But in the NBC-whatever-I-watched-production, it felt like the 4th wall was already broken and down to begin with. I desperately wanted to connect with the characters but I rarely did. Maybe children were entertained? I hope. Maybe it will inspire some little kids to pursue acting and singing? That would be nice.
Also, the lack of audience gives the viewer at home such blue balls. NBC please keep trying to showcase musical theatre on your network. But maybe try and figure out a way to merge the mediums. Because it is ignorant to think that theatre translates to film easily....and vice versa.