I saw it. Overall, I really enjoyed it, but I would be lying if I didn’t have some issues with it. Without getting into spoilerly details, I’d say the weakest aspect is the villain’s character arc. The way the villain is revealed came off as very flat, and not that well thought out. Plus, there was no villain song =/. Aside from that, I loved the other characters and there were some really good songs. Surprisingly, I didn’t hate the snowman character nearly as much as I was anticipating. Still, Disney spent too much of their promotion on the snowman, which alone turned me off from him.
Also, I have made a thread for the discussion of the potential of incorporating Frozen into Once: https://oncepodcast.com/forums/topic/potential-for-frozen-characters-appearing-on-once/