I have usually been comfortable inside the SF opera house; but I get colder than I used to... I’ll probably wear thermals under.
When I was little, my father and I would have a father-daughter day for the Nutcracker. The ballet and then lunch at a restaurant with lace curtains! French of course. It was dad after all, lol. In my teens I did the ballet season with my mum. Mum also did the symphony season, so I’d go for a few of those. Opera has always been me and friends. The ‘rents didn’t do opera, it’s interesting.
Although, my mum and I would go have a gawk at the opera opening to spy on, like, our family doctor guru. Lolol! One year his wife wore a vine of ivy... wrapped all around and I swear on top of her head!
...of course, we’d duck and hide and runaway so as not to be spotted... quite funny