Alex and I discussed a few weeks back whether Wagner would ever be a possibility at NYCO. A astutely pointed out that, even with some modification, the orchestral needs could probably not be met for most, if any of Wagner's works.
I did some browsing on the topic, just to see what others had to say about it, and found this interview with Paul Kellogg from August of 1997--the eve of his debut season with NYCO.
It's fun in retrospect: his lamenting that they cannot do Strauss' Capriccio, which they did just this season (The ever terrirfic Alex Ross sums it up brilliantly in this article). And of course having some perspective 8 years later on the Glimmerglass/NYCO relationship makes it entertaining.
The Wagner issue comes up--and while not ruling it out entirely, Kellogg basically confirms the orchestral personnel problem. Anyway, take a look at the interview--it's fun from our 2005 POV.