I actually think a film version could work very well. The whole show is spectacle. A film can go so much further with special effects and locations and just commit to presenting these songs as wild as the original production. It could even have an anthology feel to it, presenting the different songs as self contained short films about the cats singing them, tying them to the junkyard as a framing device.
Now, I don't think Tom Hooper is the director to go with, but I don't particularly care for any of his work that I've seen (The King's Speech, Les Miserables, The Danish Girl). Who knows? Directors surprise you sometimes.