Blumlein still works pretty well for full orchestra. The old standard for large classical ensemble is a Decca Tree with omni microphones (or center cardioid and omni for the L/R). ORTF or NOS (similar coincident patterns) works very well and spaced omnis as well. I have used MS for chamber orchestra but I don't like it as well for a full symphonic orchestra. The fewer mics the better IMO. When you see 37 mic's hanging from the ceiling of Severance Hall 33 of those are not usually being actively used. They are there to augment the "live" amalgamation recordings and are beyond the scope of most folks needs.

A huge amount depends on the acoustics of the venue, whether it's a public performance or principally a recording session, and whether you have a free reign to place mics where you want.

The traditional route is to use a centre cluster, omni outriggers spaced wide out front and spot mics for particular orchestral sections or instruments (e.g. harp). The centre cluster could be an X-Y cardioid pair, X-Y standard Blumlein pair, M-S pair, M-S Blumlein pair or something more esoteric such as a Decca Tree. My practice is to use delay on outrigger tracks so that even far L or R sounds are heard first via the centre mics before reinforcement by the outriggers. It's unlikely that a standard A-B spaced pair would give acceptable results in the conditions you describe.

I would not use more than one Blumlein set, as this will lead to irreconcilable phase issues in the mix.

Consider AB or NOS, with spots if needed.

Where was this recorded?

Recorded live, December 2013 in Memorial Hall at the University of North Carolina - Chapel Hill. Recorded another concert there last week. Looking forward to the mix (and more videos).

Thanks, I enjoyed listening.