Check out the seating map on the site for the show - they indicate the different accessible locations. They are areas with a row of folding chairs that can be removed to fit a wheelchair.
The last time I saw La Nouba (in '07), they sat me in one of the accessible sections (I'd have complained but we got there late and the show had already started - we were lucky that they let us sit down right away instead of stand with other latecomers in the entryway to the theatre). (I have mobility issues and use a service dog, my friend had MS, and we used the elevator to get up to the theatre level.) We were put in the rightmost h/c section on the entry floor level (the walkway between the 100 and 200 levels). It was empty, so we sat in the leftmost seats of the section to try to get better seats (the seats I paid for would've been a bit more to the left and they were higher, in the 200s).
My friends didn't mind the seats, they were just amazed at their first-ever Cirque show, but since I've seen Cirque shows before, incl. La Nouba, I didn't like them all that much. I think they have h/c seats at the top of the theatre - I don't know how the view is from all the way up there, but I have sat in the 200s and prefer them for all Cirque shows - you wouldn't be craning your neck up sitting there. Try to get center section, too, even if it is the lower h/c section.
Definitely do go, though!!! :-D
