Wait some more.

You wait some more, then something quite remarkable happens: a taxi pulls up and takes away the first two people in the queue.

A few moments later, another cab shows, and the queue shortens by three more. Along comes a third vehicle - it's almost like they have radios and are telling their friends in the vicinity that there are miserable rich people waiting outside the opera for a lift back to their mansions.

Pretty soon, you're first in line. Along comes a black cab. The driver pulls up and waits for you to get in.

At this point, you overhear the couple behind you deciding that all this waiting is just too much, and agreeing to visit a nearby pub.

You can:

Eagerly take the taxi, it's f-f-f-freezing!

Snub the taxi driver and follow the couple to the nearby pub.

Recall all those newspaper stories about murderous taxi drivers and walk to your hotel after all.