Have they brought the revisal to London? I bet she'd be brilliant--and certainly better than the very talented, but even more very miscast Mazzie who was a Barbara Cook when, for all the reasons discussed here, they needed a Betty Buckley.
I hate to speak ill of Mazzie considering how talented she was and how sad her loss was BUT I feel she suffered (probably was directed to do this from what I read at the time) by the whole push to make Margaret more sympathetic. They did that with the remake where Julianne Moore played the role. For some reason the kept emphasizing that Margaret is a victim too. Buckley mentions this in the discussion that abusers are usually abused themselves but that doesn't mean they need to be made to be sympathetic.
Buckley and Piper Laurie made the role work because they weren't afraid to be cruel and lets face it they were bitches. I've read some reviews of the film call Margaret a misogynistic character so maybe that's why there was a move to make her less fierce.
As much as they talk about how they've had productions all over the world etc. I still think Buckley is the reason why the show lives on in infamy. She's thrilling in those clips.