As Mark_E said it would need a new set for a tour. Maybe they should tour it first and then bring it back to London with the new set.
Of course I would prefer for both tour and London to run parallel.
Apart from the chase scenes, and the finale, the stage doesn't need to be too big either.
I'm going to be optimistic for the time being. I love the show, and I will keep taking more and more people to it as long as I can.
If it does close in London for too long, I will just mount my own production instead.
Once you start to spread it, Baby, if you let it, Love comes right on back to you . . .