Once Upon a Several Years Ago...

 thatmonotrile and I were singing carols to each other over the phone at some ungodly hour of the morning. (Don't ask.)

Suddenly she faded out during "dashing through the snow" and I waited in vain for her to finish before realizing she'd fallen asleep on me.

I don't remember how Chico, the Late and Great Bull Terrier, figures into all of this.